System and method for carbon sequestration of dried lignocellulosic biomass

Abstract

Systems and methods for sequestration of dried wood in an aboveground storage system. Wood product is dried in a two-stage drying process. A first drying stage is performed using a gasifier-based generator where a portion of the dried wood product from the second drying stage is used as an energy source. A second drying stage is performed using renewably generated forced air (e.g., heated air that is generated using solar power) and / or surplus electricity from the gasifier-based generator. The second stage provides a significant portion of the removal of moisture from the wood product in order to limit the carbon footprint of the drying process. The dried wood product is stored in a specially designed above-ground container constructed from modular panels. The container is configured to keep out water and insects in order to prevent decomposition and / or infestation of the stored dried wood product.

Description

SYSTEM AND METHOD FOR CARBON SEQUESTRATION OF DRIEDLIGNOCELLULOSIC BIOMASSCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing date under 35 U.S.C. § 119(e) of U.S. Provisional Application Serial No. 63 / 564,243 filed on March 12, 2024. the entire disclosure of which is incorporated by reference in its entirety.FIELD

[0002] Embodiments relate to systems for drying and stable long-term aboveground storage of wood product.BACKGROUND

[0003] Carbon removal is the process of removing carbon dioxide (CO2) from the atmosphere and sequestering it or otherwise locking it away for a substantial period of time, e.g., decades, centuries, or millennia. Different approaches to carbon removal and sequestration may come with different costs, risks, and benefits. One approach aims to prevent additional CO2 or other greenhouse gas, such as methane (CH4), from entering the atmosphere, rather than remove CO2 or CH4 already in the atmosphere, by collecting material which would otherwise release CO2 or CH4, e.g., due to decay, combustion, etc., and sequestering it in a form which prevents that release. With less entering the atmosphere, as the CO2 or CH4 already in the atmosphere dissipates or is naturally removed, e.g., due to photosynthesis, atmospheric levels will drop. The carbon in this collected material, which would otherwise be released into the atmosphere as CO2, CH4, or other greenhouse gases, may be referred to as CO2-equivalent (CO2e).

[0004] Typical costs of carbon sequestration include the dollar cost in labor, energy, and material s / equipment to implement and maintain the sequestration process, acquire the material to be sequestered, acquire, and maintain the location and facilities at which the material will be sequestered, process the material into a form suitable for sequestration, and store or otherwise complete the sequestration of the processed material. One may further consider the opportunity cost of favoring one method of carbon removal over another. A typical benefit is at least a substantially permanent net reduction in atmospheric carbon dioxide and the attendant direct or indirect environmental, social, and economic benefits resulting therefrom. Typical risks include a risk that the method ofsequestration will fail, resulting in the release of the sequestered carbon in the form of CO2 or other greenhouse gases, that a byproduct of the sequestration process will release more CO2 or other greenhouse gases into the atmosphere than is sequestered thereby, or that the net cost of the sequestration process will exceed any cost savings indirectly achieved via the environmental changes, e.g., lower health care or lower property insurance costs, or directly achieved, such as via sale of carbon offsets / credits.

[0005] Typically, the sequestration of CO2 involves processes which themselves emit / release CO2, e.g., from the generation of energy to power the sequestration process. Accordingly, the effectiveness of carbon removal and sequestration processes is typically measured as a function of the net amount of carbon dioxide equivalent (net CO2e) removed / stored by that process, specified, for example, in net tons, and may be specified in terms of the costs associated therewith including both monetary and non-monetary costs. One of the biggest issues for the carbon removal industry is minimizing the cost per net ton of CO2e removed / stored since the profit margin for the sale of carbon credits (based on net tons CO2e removed) is directly related to the cost of the net removal / storage of CO2e. For example, an increase in process CO2e emissions associated with removal, all other factors held constant, increases the cost of removal per net ton of CO2e removed because fewer net tons of CO2e are removed after accounting for the increase in process CO2e emissions. However, this increase in cost may be offset by lower process costs elsewhere because processes that emit more CO2e may cost less to operate relative to lower-emitting processes. On the other hand, a decrease in process CO2e emissions increases the net tons of CO2e removed, thereby decreasing the cost of removal per net ton of CO2e removed, all other factors held constant, but may be offset by the higher costs of implementation of lower-emitting processes.BRIEF DESCRIPTION OF THE FIGURES

[0006] Figure 1 depicts an example method for drying and storing wood product for carbon sequestration.

[0007] Figure 2 depicts an example system for wood drying according to an embodiment.

[0008] Figure 3 depicts an example process workflow for wood drying according to an embodiment.

[0009] Figure 4 depicts an example of a long-term storage container according to an embodiment.

[0010] Figure 5 depicts an example of a roofing support system and a top view of a pallet layout according to an embodiment.

[0011] Figures 6A and 6B depict examples of a roofing support system including one or more jacks according to an embodiment.

[0012] Figures 7A and 7B depict examples of a roofing support system including one or more wedge assemblies according to an embodiment.

[0013] Figure 8 depicts a side view of an example of a support system for a long-term storage container according to an embodiment.

[0014] Figure 9 depicts a top down view of an example of the support system of Figure 8 for a long-term storage container according to an embodiment.

[0015] Figure 10 depicts a side view of an example of a support system coupled with a drainage system for a long-term storage container according to an embodiment.

[0016] Figure 11 depicts a top down view of an example of the support system coupled with a drainage system of Figure 10 for a long-term storage container according to an embodiment.

[0017] Figure 12 depicts a side view of an example of a grating-less support system coupled with a drainage system for a long-term storage container according to an embodiment.

[0018] Figure 13 depicts a top down view of an example of a grating-less support system coupled with a drainage system of Figure 12 for a long-term storage container according to an embodiment.

[0019] Figure 14 depicts a top down view of a roofing and drainage system for a longterm storage container according to an embodiment.

[0020] Figure 15 depicts a side view of a roofing and drainage system for a long-term storage container according to an embodiment.

[0021] Figure 16 depicts a side view of a J- shaped attachment for a roofing and drainage system for a long-term storage container according to an embodiment.

[0022] Figure 17 depicts a side view of a W- shaped attachment for a roofing and drainage system for a long-term storage container according to an embodiment.

[0023] Figure 18 depicts a side view of a roof support and drainage system for a longterm storage container according to an embodiment.DETAILED DESCRIPTION

[0024] Embodiments provide a lignocellulosic biomass drying process and long-term storage system which may be used with any lignocellulosic biomass material, including all varieties of terrestrial plant material, including leaves and grasses, wherein “lignocellulose” refers to the variety of polymeric structures that are composed (in varying proportions) of cellulose, hemicellulose, and lignin. As will be described, in at least one implementation, the disclosed embodiments are applied to wood product, a type of lignocellulosic biomass which generally have a lower moisture and nutrient content relative to other types of lignocellulosic biomass.

[0025] In an embodiment, the lignocellulosic biomass comprises a wood product, such as in the form of wood chips or saw dust, and a two-stage drying process is provided to dry the wood product where a first stage may be performed using waste heat and electricity, such as from a gasifier-based generator (e.g., a generator that uses a portion of the wood product from the process to generate energy), and a second stage may be performed using renewably generated forced air (e.g., generated using solar power), wherein the second stage provides a significant portion of the removal of moisture from the wood product. The resultant dried wood product may then be pressed into a compacted form, i.e., densified, into briquettes or other shapes for compact storage in a suitable above-ground container. The above-ground container may be made from panels of fiber-reinforced plastic (FRP) and / or any other suitable material that are bolted and / or fastened together to create a larger composite structure. The base of the storage container may or may not be comprised of the same panels as the sides and roof of the structure, or may be absent entirely, or may be comprised of a different material such as asphalt or concrete. A roofing support system may be used in which the dried wood product that is stored in the container is used to hold up or support at least partially a weight of the roof of the container. The storage container is configured to keep out water and insects in order to prevent decomposition and / or infestation of the stored dried wood product. In an embodiment, the wood product may be dried, then densified, and then stored indefinitely. In another embodiment, the wood product is densified before drying, then loaded into a container or long-term storage system, and then dried while in storage. A process control model is used to optimize controllable inputs (e.g., fan speed, fan on / off status, rate of heat supplied to ambient air, percentage of biomass that is gasified to produce electricity and waste heat for drying) to achieve the minimum cost per net ton of CO2e stored in thecompact dried form, e.g., briquettes, given feedback from measured conditions (e.g., temperature and relative humidity within the drying wood product), current / forecasted external conditions (e.g., external / ambient temperature and relative humidity), and characteristics of the incoming wood product (e.g., particle or chip size and initial moisture content).

[0026] One method for carbon removal / sequestration utilizes long term storage of biological material such as a wood product or other lignocellulosic biomass. In an example, wood is able to resist decay, and therefore its carbon remains captured within the wood’s lignocellulosic structure, for millennia when it is kept sufficiently dry and protected from environmental stressors such as sunlight, insects, and excessive moisture. Exclusion or removal of excessive moisture may be a key determinant in the decomposition process; freshly cut wood often has a moisture content (MC) exceeding 50% on a wet basis (i.e., when including moisture in the total weight of the wood), and fungal and microbial decay readily occur unless the wood is dried to about 17%-23% MC or lower (where MC is a function of the water activity which, at equilibrium, is equivalent to the relative humidity, wherein the MC may be lower than, for example, 17% at a water activity level below which biological decay cannot occur). Excessive moisture also amplifies the effects of physical degradation caused by ultraviolet (UV) rays, promotes nonenzymatic depolymerization in wet or waterlogged wood, and renders wood on land habitable to pests such as beetles and termites. Biological decomposition of wood stops under sufficiently desiccating conditions. Dry wood that is protected from moisture has been preserved for several millennia, with only minor chemical and morphological changes evident upon microscopic examination. It can thus be anticipated that wood, dried to, for example, 11-12% MC in an environment, for example, with a water activity / relative humidity below 70% and protected from the elements, will not measurably decompose, and that the carbon captured in that wood will remain there indefinitely assuming those conditions are maintained.

[0027] Drying may be performed using all, or a significant portion of, renewable energy, particularly where access to equipment for effecting rapid drying is unavailable or cost- prohibitive, but, because of the high required throughput, such processes, alone, may be insufficient for use with the disclosed embodiments. Alternatively, to effect rapid drying, high-temperature gas-powered dryers can be used (without, or in conjunction with,gasifying or burning a portion of the biomass to generate waste heat for drying), which may provide a cost-effective approach when high throughput (i.e. , rapid drying) is desired to achieve a low overall cost per unit product produced. However, the “carbon footprint” (in the form of emitted carbon dioxide (CO2)) of employing such gas-powered dryers, and / or gasifier-based generators, is high, thereby reducing net CO2e removed, because the heat used to effect rapid drying is generated by the combustion of fossil fuels or biomass, which emits significant quantities of CO2 into the atmosphere, rather than from solar energy or another renewable source, which emit much lower quantities of CO2 into the atmosphere. The disclosed embodiments, as described herein, relate to an optimized drying process which optimizes, dynamically or otherwise, the drying processes using multiple drying technologies (e.g., drying in different stages using waste heat and / or renewably generated forced air, whether heated or ambient), such that the cost (monetary and / or non-monetary) of drying and densifying the biomass (per net ton CO2e removed) is minimized, and utilize physic al / mathematic al principles that provide a controls / optimization model for the inputs and parameters that are manipulated to control the drying and densification process to minimize the cost per net ton CO2e removed.

[0028] Embodiments provide an improved drying process and system that minimizes the cost per net ton of CO2-equivalent (CO2e) stored in the form of dried and compressed wood briquettes, subject to the constraints of a specified drying time (for example, based on throughput needs), an initial moisture content, a specified final moisture content, the costs of the drying equipment, and / or and a specified maximum allowable degree of decomposition of the wood product during drying (since, for example, wood that is dried very slowly could experience biological decomposition during the drying process). The drying is performed in one or more drying operations using forced ambient air and / or air that has been heated, with the source of heat being derived from a combination of, for example, solar energy (to maintain a low “carbon footprint” for the drying process) and / or waste heat resulting from gasification of a percentage of the incoming wood product by one or more generators to generate electricity which powers the briquetting machines and / or additional drying. The drying process may be performed using a separate drying system and / or a drying system coupled with or otherwise attached to or made part of the storage system / container. Generators may be employed for providing electricity to operate both the briquetting process and to provide additional energy to power one ormore of the drying stages. A control system, using a model as described herein, balances, or otherwise optimizes, the use of renewable and non-renewable energy to achieve a minimum cost per net ton of CO2e stored in the form of dry wood briquettes while maintaining a specified process output, e.g., less than a predefined value, specified as a dollar or energy cost, per net ton of CO2e stored. The costs may be defined in terms of monetary value, but the dollar cost per net ton of CO2e removed includes the cost of everything involved in the process of drying and densifying wood waste and then placing this dried and densified wood waste into durable aboveground storage.

[0029] Figure 1 depicts an example method for drying and storing wood product for carbon sequestration in an above ground storage area. The term wood product is used here, but the method and systems described may be applicable to any type of lignocellulosic biomass that can be stored indefinitely in a stable dry state and that sequesters carbon in its chemical structure. The method may be performed by any combination of the components indicated in Figures 2-3 and may be implementation dependent. Additional, different, or fewer acts may be provided. The acts are performed in the order shown or other orders. In an example, the wood product may first be densified, then stored, and then dried while in storage. In another example, the wood product may be dried, then densified, and then stored. In yet another example, the wood product may be densified, then dried, and then stored. The acts may also be repeated. Certain acts may be skipped.

[0030] At act A110, wood product is acquired. The wood product may be acquired from a variety of sources, in any form, and at any point prior to the drying process. For example, the wood product may be produced / grown and harvested or otherwise collected for the specific use as described herein. Alternatively, or in addition thereto, naturally growing or grown wood product may be harvested or collected for use as described herein. Alternatively, or in addition thereto, wood product, naturally or specifically grown for use in other industries, e.g., excess or waste products thereof, may be acquired or collected for use as described herein. The wood product may be collected and stored on site or delivered to the drying system as needed. The wood product may include any type of materials that include fibers of lignocellulose (which contains cellulose, hemicellulose, and lignin). The wood product may come from any wood species in any condition, for example as logs, branches, sticks, etc. Examples of wood species that may be usedinclude Radiata Pine, Scots Pine, Red Pine, Yellow Pine, Maple, Alder, Birch, Aspen, Balsawood, Beech, Ash, chestnut, Yew, spruce, fir, among other species. Other plants such as shrubs or other “woody” plants may also be used provided that they contain lignocellulosic biomass with a carbon to nitrogen ratio above 80. The wood product may be collected in any form such as logs, twigs, needles, brush, sawdust, wood shavings, grinding dust, forest residue wood obtained in the thinning of forests, and / or wood chippings or wood chips. Processed wood product such as wood sheets, green lumber, pre-treated lumber, beam, plank, wood chip, wood powder, dimensional lumber, veneer, panels, engineered wood such as plywood, laminated veneer lumber, and wafer boards may also be used, such as when considered scrap or waste or otherwise designated for disposal via other means which might otherwise release the carbon therein.

[0031] The wood product may contain water absorbed by the lignocellulose fibers and additional liquid water contained inside the voids and channels of the wood product. The amount of water contained in the wood product is referred to as the moisture content (MC) of the wood product and is typically expressed as a percentage by weight. Specifically, the MC of wood is expressed as a percentage of the weight of the water contained in the wood product relative to the total weight of the wood (including water as well as all other components of the wood). The maximum percentage of water that can be absorbed by the fibers in the wood product is referred to as the fiber saturation point (FSP). The fiber saturation point also corresponds to the MC during the drying process at and below which only water bound in the cell walls remains. Different wood products have different fiber saturation points which may range from, for example, 20% to 30% by weight. The average FSP in many types of wood is approximately 26%. Prior to reaching the FSP during drying, the wood product will preferentially lose free water (i.e., water that is not bound in the cell walls). Below the FSP, the wood product will begin to lose moisture in the form of bound water. As the MC of wood drops below the FSP, the wood product will continue to lose moisture until it eventually stabilizes at a value that is commensurate with the surrounding moisture in the air. This MC corresponds to the equilibrium moisture content (EMC). How much bound moisture may be lost during drying depends upon the temperature and relative humidity (RH) of the surrounding air. When the RH is higher than that corresponding to equilibrium with the wood MC, no bound water will be lost. Under these conditions, the wood will absorb water from the airuntil the corresponding EMC is reached. At 0% RH, all the bound water in the wood will be lost, a condition known as “oven dry,” so-called because a kiln or oven is typically required to completely drive out all moisture. Depending on the type of wood product, during the drying process a particular MC may never be uniformly reached throughout the thickness of the wood product. A moisture gradient may develop where the outside (shell) is drier, with the interior (core) still wet. The wood product may be shredded or processed to increase the surface area and allow moisture from the core to be removed more easily. The EMC changes based upon the fluctuating temperature and relative humidity of the surrounding air. The MC of a particular piece of wood product may vary based on its state upon collection (e.g., still growing or already cut / broken), its condition and age at the time it was obtained (e.g., the duration of time that the wood product spent lying in a field), the conditions of the environment from which the wood product was obtained (e.g., a rainy environment), the environmental conditions experienced during transport to the drying process, or combinations thereof. During the collection of the wood product, the MC, EMC, and / or FSP may be measured and / or calculated for use as a drying parameter in the drying process. For example, wood product with a higher FSP may require additional drying time and / or heat. Wood product with a lower MC may require less heat and / or time to dry.

[0032] The wood product may be acquired from any location and may be stored for a period of time or processed immediately. Green wood, for example, may be allowed to dry in ambient air if the RH of the external environment is low enough and if the amount of decomposition that occurs during the slow, unassisted drying process is not unacceptably high.

[0033] In an embodiment, as part of the collection process, the wood product may be reduced in size prior to drying through comminution. The wood product may include a composite structure that includes fibers that are made of cellulose and a matrix composed of hemicellulose and lignin that binds the fibers together. Reduction of the wood product’s size includes where large particles, chunks, logs, branches, lumps, etc., are fractured into smaller particles. The comminution process may use cutting, shearing, tearing, grinding, impact stress, compression, friction, or a combination of these processes. These processes may, for example, by creating irregularly shaped particles,also increase the exposed surface area of the resultant particles to further enhance the drying process.

[0034] The output of the wood collection process is a collection of wood product that is ready to be dried and has a known moisture content and weight, for example measured by one or more sensors.

[0035] In an embodiment, instead of being dried before being densified, the wood product may first be densified into briquettes or another form factor, for example, as described below in act A 130, and then dried. In an example, the method includes densifying relatively high-moisture biomass, loading it into a storage container, and then using heated or ambient air (forced through the container) to dry the densified biomass while it is in storage.

[0036] At act A120, the wood product is dried. The drying process may include multiple stages that may be performed in different orders. In a first stage the wood product is dried to an intermediate MC using, for example, waste heat and electricity from a gasifierbased generator that is fueled using a portion of the wood product from the process. A second stage dries the wood product to the EMC or to a different MC (either higher or lower than the EMC) using, for example, renewably generated (e.g., using solar energy) low temperature forced air. The second stage may provide a significant portion (for example, more than 75%) of the removal of water (moisture content) from the wood product. The drying mechanisms used in the first stage and second stage may be interchangeable. For example, the first stage may be performed using renewable energy as described, while the second stage utilizes waste heat. One or more of the first and second drying stages may be repeated. A single drying stage may also be used depending on the drying needs of the acquired wood product. The selection of which drying process is used in a particular drying stage may be controlled by the process control model. In an example, the cost per net ton of CO2e removed may be minimized by drying with low- temperature forced air first (until the FSP is reached), and then using the waste heat from the gasifier-based generator to achieve a final MC below the FSP. Different metrics may be used. The output of the drying process is a dried wood product that is acceptable for briquetting, e.g., that meets a target MC defined by the model.

[0037] In an embodiment, there is a continuous mass input rate of the wood product to the drying stage. The rate of progression of the wood product through each of the steps maybe maintained in order to avoid material accumulations in the system. The rate may be altered during the drying process depending on how the drying proceeds. Prior to, during, and after the drying process, sensors take various measurements of the wood product. For example, a moisture content of the wood product is measured initially prior to being input into a first stage dryer, before a second stage dryer, and after the second stage dryer. A sensor or other equipment may also be used to measure the particle size distribution of the wood product prior to input into the drying stage. Screens may be used to separate different sizes of particles as the particle sizes of the wood product may not be uniform. A chipper or hammermill may be used to reduce the size of larger particles as larger particles may take longer to dry.

[0038] The wood product may be dried in batches or alternatively in a continuous process. In a batch process, the acquired wood product may be divided into relatively equal sized lots or batches, and / or into lots / batches based on actual or estimated MC. A size of each batch may be set based on a weight or volume of the wood product, and may depend on the capacity of the drying mechanisms, e.g., to maximize efficiency thereof such as to avoid heating up a dryer for less than the full capacity thereof, and expected delivery of additional wood product for drying, e.g., one may wait to dry a batch the size of which is less than the capacity of the dryer when more material is expected within a short amount of time. Batches may contain one type of wood product or wood product of a certain MC. Alternatively, there may be a mixture of different species or MC of the wood product. The control model as described below may take into account the MC or measured or expected heterogeneity in the input wood product. In one example, the MC of the wood product may be measured so that the wood product is separated by MC and / or particle size prior to input so that each batch dries at approximately the same rate. For the drying process, each batch is processed at each stage before moving on to the next station / drying stage. In an example of the two-stage process, a batch is input into the first station / stage and completes the drying process of that stage prior to being moved to the second station / stage. The batch then completes the second station prior to being moved to a subsequent station, for example a briquetting station and / or fed to a gasifierbased generator. Suitable buffering / holding / storage areas, or variable rate / volume conveyance mechanisms, may be provided to store or otherwise buffer the output of one stage while awaiting the availability of the next stage so as to allow the next batch tocommence drying. Once the densification process, e.g., briquetting, is finished the batch is stored. Alternatively, the wood product may be first densified and then loaded into a container without being dried. The wood product in the container may then be dried in place without being removed from the container. Once a first batch is completed in the first station, a second batch may be input into the first station. Each stage may include different numbers of stations to minimize or eliminate queuing. For example, if the first stage takes twice as long as the second stage, the first stage may include twice as many drying stations so that none of the drying stations are idle. A scheduling algorithm may be used by the control system to move batches between stages / stations. When separate drying apparatuses are used requiring a batch to be moved from one to another, the batches may be sized or otherwise contained in a container which facilitates rapid / efficient evacuation from the drying apparatus and rapid reloading so as to, for example, minimize the loss of residual heat therefrom during the transfer.

[0039] In a continuous system, wood product may be continuously moved through at least a portion of the entire system, for example using conveyors, tunnels and other interconnections which convey the wood product through and / or between stages. A continuous kiln, for example, dries the wood product as it moves continuously through the kiln. In a continuous system, the wood product may never stop moving. The size of each drying apparatus, e.g., the length of the drying tunnel, may be defined and / or the speed and / or volume of the conveyance mechanism therethrough may be set and adjusted, such as by the control system described in detail below, in accordance with, for example, the volume of material to be processed and the anticipated time needed to complete the processing, available energy, etc. Alternatively, a single dryer may implement all stages of the drying process, switching between drying modes as directed without having to move the wood product. In an embodiment, the wood product, for example densified biomass, may be loaded into a container and then dried while being stored inside the container. The drying system may be integrated into the container or may be attached to the container to effectuate the drying.

[0040] Figure 2 depicts an example system for wood product drying. The system includes a first stage dryer 120, a second stage dryer 130, a gasifier-based electric generator 140, a renewable power / heat source 150, a briquetting machine 160, and a control system 170. As depicted in Figure 2, wood product 102 is input into the first stage dryer 120 whichoutputs removed water and first dried wood product 104. The first dried wood product 104, or at least a portion thereof, is input into the second stage dryer 130 which outputs removed water and further dried wood product 106. The further dried wood product 106, or at least a portion thereof, is input into the briquetting machine 160 which outputs removed water, briquettes 114, and waste heat. The system further includes a gasifierbased generator 140 which may, for example, take as inputs, at least a portion of the dried wood product 104 or 106 from the first or second stage dryers 120 or 130 and outputs waste heat 110 and electricity 108 that are used by the first stage dryer 120 and / or briquetting machine 160. Excess electricity may be further used to power additional drying processes and / or stored for later use, such as in batteries, capacitors, or other storage, such as inertial or gravity-based storage, as described elsewhere herein. The dried lignocellulosic biomass (which may or may not include wood) fuel for the gasifier-based generator may come from sources other than or in addition to the dryers 120 or 130, for example if there is insufficient lignocellulosic biomass from the second stage dryer 130. The system further includes a renewable power source 150 (such as a solar array) that provides heated air 112 and / or electricity for the second stage dryer 130 and other components of the system. Additional sources of electricity or heat may be provided by alternative sources. As was noted above, excess energy, such as in the form of electricity or heat, may be further used to power additional drying processes and / or stored for later use, such as in batteries, capacitors, or other storage, such as thermal, inertial, or gravitybased storage, as described elsewhere herein. The control system 170 adjusts inputs and outputs of the various components in order to optimize for the lowest cost per net ton CO2e removed, given the constraints and environmental operating variables for a particular system where the drying, briquetting, and storage occur. For example, the environment for a particular system at a particular site may be colder or hotter or have a higher or lower RH or otherwise may experience different and varying weather conditions. The weather variables may affect the extent to which the use of the second drying stage is advantageous compared to the first drying stage that uses waste heat from the gasifier-based generator. One additional constraint at every site may include a requirement of a certain mass flowrate of wood into the process that will yield an approximately equivalent mass flowrate of densified briquettes at the end of the process (for storage). The lowest cost per net ton CO2e removed may further include limiting thecarbon footprint of the drying process as an increased carbon footprint may increase the cost while decreasing the net benefit of the process. The carbon footprint is the total amount of greenhouse gases (including carbon dioxide and methane and other C02e) that are generated by the drying, briquetting, and storing process. The carbon footprint may depend on various factors such as how electricity or heat is generated, how the wood product is moved, how the wood product is stored, etc. Additional components such as fans, belts, wiring, etc. are not shown.

[0041] The system includes a gasifier-based electric generator 140 that supplies waste heat 110, a byproduct of the generation of electrical power, and electricity 108 to, for example, at least the first stage dryer 120 and / or the briquetting machine 160. The dryers 120, 130 may be any device that generates heat or airflow, or otherwise effects the removal of moisture from the wood product. In one embodiment, the gasifier-based generator 140 converts some portion of the wood product to wood gas which is used to generate electricity 108 that is used to power, for example, the first stage drying process (for example heating elements to heat air, if not already sufficiently heated, e.g., via waste heat as described below, or if ambient temperature air is insufficient, and fans to blow the ambient or heated air over and through the wood product) and the briquetting machine 160. The gasifier-based generator 140 also generates waste heat 110 that may be used in the first stage drying process. The gasifier-based generator 140 works by converting some of the wood product to a usable fuel such as wood gas. The substance of a solid fuel such as the wood product is primarily composed of the elements carbon, hydrogen, and oxygen. In one type of gasifier that may be used, the wood product is heated by combustion of a part of the fuel. The combustion gases are then reduced by being passed through a bed of fuel at high temperature. In complete combustion, the main combustion products are carbon dioxide and water. Oxygen from the fuel is incorporated in the combustion products, thereby decreasing the amount of combustion air needed. The carbon dioxide and water vapor are converted (reduced) as much as possible to carbon monoxide, hydrogen, and methane, which are the main combustible components of the wood gas (also referred to as producer gas). Any type of gasifier-based generator 140 may be used. In an embodiment, the gasifier-based generator 140 provides power and waste heat 110 to the first stage dryer 120. The first stage dryer 120 may be any type of dryer. In an embodiment, the first stage dryer 120 uses fans to blow air with a RH lower than theRH that would be in equilibrium with the MC of the wood product. Waste heat 110 may also be used to speed up the drying process. The first stage dryer 120 removes moisture from the wood product 102 until the wood product 102 reaches a target MC (such as its FSP). The wood gas is burned to produce electricity 108 that is used to power components of the system or stored for later use in, for example, batteries. In an example, the electricity may be used to power fans or other air-moving devices to blow air over the wood product in the first-stage dryer 120 and / or second-stage dryer 130 and / or to power the briquetting machine 160. The waste heat 110 may also be used in the first stage or second stage of drying. The amount of wood product 102 that is used as fuel and the amount of waste heat 110 / electricity 108 produced is controlled by the control system 170 as detailed below. In an embodiment, the use of the gasifier-based generator 140 is minimized as a minimization of the gasification-based energy consumed, as well as a minimization of the wood product fuel that is used by the gasifier-based generator 140, reduces the carbon footprint of the drying process. Drying parameters for the gasifierbased generator 140 may be optimized by the control system 170 so that drying effected in the first stage by the electricity 108 / waste heat 110 from the gasifying is balanced with drying effected in the second stage using ambient and / or solar-heated air in order to minimize the cost per net ton of CO2e stored in the form of densified wood.

[0042] The system includes one or more dryers including dryers 120 for a first stage which are powered by the electricity 108 and waste heat produced by the gasifier-based generator 140. The electricity 108 and waste heat produced by the gasifier-based generator 140 may also be stored for later use by the system. Dryers 130 for a second stage may be powered by renewable sources 150 (such as solar air heaters and / or solar photovoltaic panels) and remove additional moisture from the wood product until the wood product reach a target final MC. Additional stages may be used, such as a third stage that uses a third method of drying or different equipment than the first or second stages. The stages may be interchangeable and may be performed in any order. In an example, the second stage may be performed prior to the first stage. More than one drying stage may also be used. For example, two or more instances of the second or first stage may be used. The dryers 120, 130 may include any type of dryer that effects a reduction in MC of the wood product . The dryers 120, 130 may include forced air dryers, heated air dryers, microwave, or other dryers.

[0043] The use of a renewable power / energy source 150 in the second stage reduces the carbon footprint for the overall process. The renewable power source 150 may provide heat and / or electricity directly or indirectly (such as via an intermediate storage mechanism), e.g., to produce heat and / or drive fans or conveyance mechanisms, for the first stage, second stage, or any other process described herein. Renewable power sources 150 may include, for example, solar, hydro, wind, wave, geothermal, etc. Solar air heating is a renewable energy heating technology that provides heated air that removes moisture from the wood product without oxidizing a fuel. The heated air may be provided directly by converting sunlight into heat or by using, for example, solar panels that convert sunlight into electricity which then may be converted into heat using a heating / drying apparatus and / or used to power fans to provide airflow. In an example, a low-temperature solar dryer uses solar collector panels to warm air that is then passed / blown over the wood product in order to remove moisture. If the warm air has a lower RH than the RH corresponding to the EMC of the wood product, then moisture will be drawn out of the wood product. This type of solar dryer uses solar collector panels, a duct system, fans, and diffusers to heat the air and move the heated air over and across the wood product. The electricity used to run the solar dryers for the second stage may be provided by the solar system itself (for example using batteries) or by the gasifier-based generator 140.

[0044] The dryers 120, 130 for the first stage and the second stage may also use process heat that is provided from the use of other sources of energy to produce products other than power or electrical generation. Waste heat 110 may be provided by the gasifier as described above, but other sources, such as those which may provide heat or energy at low or no cost, may be used. For example, in a co-generation system, primary processing such as chemical processing, production of cement, steel or aluminum, refining, production of energy products like coal and liquid energy products, may use heat to drive the primary processing, and the unused heat remaining after the primary processing or created during the primary processing would be the process heat of such processing, and can be used in the drying system. In an example, waste heat 110 from a server farm or nuclear power generation plant may be used to assist in the drying process.

[0045] The second stage dryer(s) 130 may use solar panels and batteries, or other energy storage, that are capable of storing, collecting and / or converting solar energy. The solar panel may comprise a photovoltaic device capable of collecting and converting solarradiation into electricity. The solar panel may be used to supply electricity to a circulation fan, a ventilation fan, a rechargeable battery or other energy storage device, a dehumidifier, or a supplemental heating unit.

[0046] In an embodiment, for either first stage drying or second stage drying, fans may be used to blow ambient air having a known temperature and RH (as measured by sensors) through the wood product. The air may be injected through or near the bottom to allow the air to migrate through the mass of wood and exit at the top. Airflow may be supplied continuously until the MC of the wood product reaches equilibrium with the ambient air, for example, inferred from convergence of the RH, measured within the wood product, to the RH of the incoming ambient air, and on stabilization of the weight of the wood product which decreases during drying due to water evaporation and removal. Intermittent and / or constant fan schedules, as well as varying fan speeds or airflow volumes, may be used / controlled by the control unit when using either a constant power source or an intermittent source such as solar panels with minimal battery backup.

[0047] The system further includes one or more components such as fans, belts, containers, and other machinery that is used to move the wood product 102, water / moisture, or heated air. These components may use electricity or other inputs that are taken into account by the control system 170 described below. These components may be powered by the gasifier-based generator 140 or the renewable power source 150, and / or from an energy storage device replenished thereby.

[0048] The system further includes one or more sensors (not depicted) that monitor the drying process and provide feedback to the control system 170. Sensors may be included that allow quantification of the waste heat and electricity provided by the gasifier-based generator. Sensors may be used in the first and second stage of drying to infer and monitor the amount of heat and electricity that is used. Sensors may monitor the throughput of the system. Sensors may monitor the MC and / or mass of the wood product at each stage. Sensors may also track environmental conditions such as the humidity and / or temperature of the forced air. For example, the system may use or include a humidity measuring device and a humidity control mechanism. Wet and dry bulb temperature measurements, relative humidity sensors (including capacitive sensors and resistive sensors), dew cells, infra-red humidity sensors and / or a psychrometer or hygrometer may be used to monitor the humidity inside and outside the drying systemincluding forced air used for the first drying stage and / or the second drying stage. MC or the humidity ratio of air may be defined as a ratio of kilograms of water vapor per kilogram of dry air at a given temperature and pressure. The MC or humidity ratio of the air may be calculated or measured based on relative humidity, wet / dry bulb temperature, and / or other measurements using psychrometries (the study of thermodynamic properties of air-vapor mixtures). A psychrometric chart can thus be used to determine the moisture content of air inside and outside the drying system. Multiple humidity or moisture measuring devices may be configured or positioned to measure relative humidity of air inside and outside the drying system. For example, two humidity-measuring devices may be provided with one positioned to measure the RH of the forced air and one positioned to measure the humidity near or in the vicinity of the wood product. The measurements from both humidity devices are provided to the control system 170 that is configured to control the various systems that effectuate the removal of moisture from the wood product 102. In an example, the control system 170 may control ventilation of the drying system in order to lower the humidity or moisture level of the forced air that is used to dry the wood product 102. Any known humidity measuring device and de-humidifiers may be used. One or more thermometer or temperature sensors may also be used to provide dry bulb temperature measurements of the interior and exterior air. Similarly, a thermostat may be provided and operated in conjunction with the control system 170 for maintaining the temperature and humidity of the forced air / drying environment.

[0049] The system may include one or more scales that measure the weight of the wood product as it passes through the first and second drying stages. A loss of weight may be attributed to moisture loss. Some loss of weight may also be attributed to decomposition depending on the speed of the drying process. The removed water / moisture and / or the dried wood product may also be measured / weighed after drying is complete. Decomposition of the wood product may be quantified by using the initial and final MC of the wood product to determine the weight loss that is attributable solely to water removal. Any additional weight loss may be attributable to decomposition of the wood product.

[0050] In an embodiment, a wood moisture meter may be used to measure the MC of a portion of the wood product during and after each stage of drying in lieu of or in addition to in situ monitoring / testing. The wood moisture meter may be a pin-type meter or apinless moisture meter, or a combination pin / pinless moisture meter, for example. Pintype meters use two or more electrodes to infer a wood sample’s moisture content by measuring electrical resistance. Since wood is a natural insulator, and water is a conductor, the more resistance there is to the electrical current, the drier the wood is, and vice versa. Pinless moisture meters (also referred to as “damage-free” meters use a specialized scanning plate to pass an electromagnetic wave through a material sample and create a reading of the average moisture content in the scanned area.

[0051] The system may include a machine for comminuting the wood product. Prior to or during the drying process, the comminuting machine may further reduce the particle size and / or change the particle shape of the wood product, e.g., to increase the exposed particle surface area and / or to make the particle size and / or shape distribution more uniform. The comminuting machine may pre-process, e.g., pre-shred, the wood product that is input into one of the drying devices to a certain size and / or shape, so as to facilitate the drying of the wood product. The comminuting machine may be or include, for example, a hammer mill or a shredder similar to a chopper, in which comminution is carried out from a gear built up by offset rollers, a chopper drum or by an impact disk. One or more screens may be used to separate the wood product into different sizes. Different sized particles of wood product may dry at different rates. Batches of similarly sized wood product may be dried more efficiently relative to batches of wood product having less uniform size distributions.

[0052] The system may include a densifying machine, for example a briquetting machine 160. Any type of briquetting machine 160 may be used. For the briquetting process, a briquetting press is used to compress the wood product into a predetermined shape. During the compression, the temperature may be raised which forces the lignin in the wood product to come to the surface and bind the wood product, rendering the formed briquette stable for further handling, and as will be discussed, to provide at least some load bearing capacity. To produce briquettes 114, the MC of the wood product may be reduced to between 8-12% MC during the drying process. In an alternative embodiment where the wood product is first densified before being dried, the briquette may be produced at a higher MC (for example greater than 12%) and then dried in- situ within the storage container. The MC may be varied depending on the type of wood product and the subsequent storage requirements. In addition, the wood product may need to be pre-shredded or reduced to a predetermined particle size, for example, 5-20 mm. The briquetting machine 160 (or a comminuting machine) may pulverize or reduce the size of the dried wood product prior to forming the briquettes 114. The wood product may be sized prior to the drying process as well. The wood product may be free from foreign substances such as sand, stones, and metal prior to briquetting. Alternatively, cobriquetting of, for example, wood shavings and another material (e.g., ground waste plastic) may also be used. The status of the wood product may be checked during the collection process and drying process in order to provide appropriate wood product for the briquetting process. The characteristics (e.g., dimensions, size, shape, density, uniformity, and / or weight) of the resultant briquettes may be implementation-dependent and various dimensions are contemplated herein. For example, briquettes may be sized for easier subsequent manual or automated handling. For example, the size and shape of a briquette may be standardized in accordance with the capacity of a machine used to move briquettes from the briquetting machine to the storage container, or otherwise standardized in accordance with the dimensions of the storage container, e.g., to hold a whole number of briquettes with a minimum of empty / unutilized space. In addition, briquettes may be shaped in a form which facilitates compact and / or structurally stable storage and / or an increase in load bearing capacity. For example, each briquette may feature a shape designed to interlock with one or more other briquettes proximate thereto to form an interlocking load bearing structure.

[0053] The system includes a control system 170 that is configured to control both the overall process from when wood product 102 is received to when it is in storage, and the individual stages of the process and interactions therebetween. More particularly, the control system 170 may control the drying and briquetting process by monitoring the processes and adjusting controllable inputs and parameters such as a fan speed, fan on / off status, rate of heat supplied to ambient air, and percentage of wood product 102 that is gasified to produce electricity 108 and waste heat 110 for drying among other variables. The control system 170 may adjust the controllable inputs to these processes and parameters and further control when to convey the wood product 102 from one drying process to another, or otherwise switch between drying processes, to achieve a minimum cost per net ton of CO2e stored in the form of briquettes 114, given feedback during the collection, drying, and briquetting process such as measured conditions (e.g., temperatureand relative humidity within the drying wood product), current / forecasted external conditions (e.g., external temperature and relative humidity), and characteristics of the incoming wood product 102 (e.g., chip size and initial moisture content (IMC)). The cost may be defined monetarily, for example in dollars or another currency. The cost may also be defined using other metrics such as the use of electricity or another commodity.

[0054] The control system 170 uses a process control model that controls the complex physical process by which moisture exits and is removed from the wood product 102 during drying, as well as the decomposition process and its dependence on process conditions. The model optimizes this process control by dictating the certainty with which controllable process inputs may be manipulated to achieve the desired outcome (described above) of achieving minimum cost per net ton of CO2e stored in the form of dry wood briquettes 114. The CO2e for a given greenhouse gas (i.e., methane (CH4)) refers to the number of metric tons of CO2 emissions that has the same global warming potential (GWP) as one metric ton of the chosen greenhouse gas. While the primary benefit for the carbon sequestration process described herein is reduction of atmospheric CO2, the term CO2e is used as it includes all the molecules that capture heat and warm the atmosphere.

[0055] The control system 170 includes at least a processor, a memory, and one or more sensors. The control system 170 provides control signals to one or more components of the drying process including the gasifier-based generator 140, the first stage dryer 120, the second stage dryer 130, the briquetting machine 160, and various components that input, comminute, move, and / or output the wood product. The signals may be sent and received through wired connections or wirelessly, for example, using a transceiver.

[0056] The processor may be a general processor, central processing unit, control processor, graphics processing unit, digital signal processor, three-dimensional rendering processor, image processor, application specific integrated circuit, field programmable gate array, digital circuit, analog circuit, combinations thereof, or other now known or later developed device for processing data. The memory may be a volatile memory or a non-volatile memory. The memory may include one or more of a read-only memory (ROM), random access memory (RAM), a flash memory, an electronic erasable program read only memory (EEPROM), or other type of memory. The memory may be removable from the control system 170, such as a secure digital (SD) memory card. The transceivermay be configured to send and receive radio frequency communication (e.g., generate, transmit, and receive radio signals) for any of the wireless networks described herein including, for example cellular networks, the family of protocols known as WIFI or IEEE 802.11, the family of protocols known as Bluetooth, or another protocol.

[0057] The control model uses one or more fixed, known, and / or measured inputs. These variables may include the MC of the wood product 102 at various points, a particle size of the wood product 102, wood type / species, amount of wood product 102 fed to the gasifier-based generator, a total electricity demand, a total electricity supply, and environmental conditions (temperature, RH, dew point, etc.) among others. Measured variables such as the MC may be measured at various points during the drying process, for example, before and after each stage of drying. The particle size distribution and wood type / species may be determined during the wood product acquisition stage. One or more screens may be used to separate or homogenize the wood product into similarly sized batches or groups based on particle size. Ambient conditions may be measured prior to, during, and / or after each stage. For example, the temperature, RH, and dew point may all be measured and input into the control model. The electricity demand and supply may be predetermined or calculated or measured in real time as the drying proceeds.

[0058] During the drying process, the control model may measure certain variables and adjust / manipulate various controls. The control model may, for example, implement a linear or nonlinear optimization of an objective function having multiple variables and may include a solver for a constrained minimization problem where the constraint may be the specified throughput rate of dried biomass and the variable to minimize would be the cost of the drying process per net ton of CO2e removed. The cost may be defined monetarily, for example by placing a dollar value on the different inputs and outputs. The input wood product may have a dollar value. The electricity used from the grid may be quantified in dollar terms. Labor or other costs may also be reduced to a monetary value. The output (for example, the price of carbon credits) may also be used. The control model considers the input variables and factors such as the drying rate (which is a function of wood particle size / shape), the initial and final MCs of the wood, the availability of biomass fuel for the gasifier-based generator, the availability of energy from renewable sources and / or from storage sources, and the ambient conditions (i.e., temperature and relative humidity). Depending on the input costs and output costs, the control model mayalter the process. For example, if input electricity prices are high, the control model may limit the use of electricity from the grid. Alternatively, if electricity prices are low, the control model may use additional electricity from the grid if the increase in the output of the system is positive. The control model would also consider the CO2e emissions associated with the use of grid electricity, as a high level of emissions decreases the net tons CO2e removed, which in turn drives up the cost per net ton CO2e removed.

[0059] In an embodiment, the control system 170 uses a statistical process control (SPC) model. The output and progression of each stage / station is measured by one or more sensors. The results (such as weight, MC, etc.) are combined with identifying data, such as date, drying station number, wood type / species, schedule, etc., in a database. The data may be analyzed to determine whether changes should be made for future wood product drying, e.g., to adjust the process for the next batch or portion of the wood product to be processed by the system or a particular stage thereof, or to reprocess a previously processed batch or portion of the wood product.

[0060] Figure 3 depicts an example of the drying process as controlled by the control system 170. In this example, the system provides approximately 10,000 net metric tons of CO2e stored per year as briquettes 114 and biochar (a waste product produced by the gasifier-based generator) when the input rate is approximately 3,000 kg / hour of wood product. The briquettes 114 may be stored and monitored above ground in specially designed containers as described below. In a first drying stage, 3,000 kg / hour of wood product are input into a first set of dryer(s) that remove moisture from the wood product down to the FSP. In this example, the wood product that is input into the first set of dryers has a MC of approximately 36%. The FSP is approximately 30%. In a second drying stage, the wood product is further dried using a second set of dryer(s), for example, powered by solar air heaters. During the second drying stage, the wood product is dried to approximately 10% MC. The dried wood product is then input into the briquetting machine 160 that generates wood briquettes 114 ready for storage. The gasifier-based generator 140 uses at least some of the wood product from the second stage of drying in order to provide heat and electricity 108 to the briquetting machine 160 and the first stage of drying. The various process streams, controllable inputs, and feedback measurements are described in Table 1 below:Table 1. Process streams, controllable inputs, and feedback measurements

[0061] For example, for the first stage drying, e.g., drying the wood product down to FSP, the controllable inputs may be the electrical power and heat supply rate from the gasifier-based generator 140. The MC of the wood product is also monitored by the control system 170 during this drying stage.

[0062] In an example of the control system 170, if the second stage dryer(s) 130 and solar air heater(s) (low-temperature solar dryers) are producing air with a sufficiently low RH and / or sufficiently high temperature, the wood product may be moved from the first drying stage to the second drying stage prior to reaching the intermediate MC, which would reduce the required percentage of wood product sent to the gasifier-based generator, or allow excess (without reducing the percentage of gasified wood) energy to be diverted to storage. In a batch processing implementation using discrete drying apparatuses for each process, the material may be moved by either manual or automated mechanisms. In a batch processing implementation using a combined drying apparatus, the control system 170 may automatically switch from one drying process to another. Still, in a continuous processing environment using separate drying apparatuses, the rate at which material is conveyed through and / or between one or more of the process stages may be adjusted, e.g., made faster, by the control system 170. Favorable conditions of temperature and RH in the second stage dryer 130 would provide for drying of the wood product with lower process CO2e emissions than the first stage dryer 120. In this scenario, the same throughput may be achieved with lower process CO2e emissions and a lower $ per net ton CO2e cost by moving wood product to the second stage dryer 130 at a higher MC than is otherwise the case. Thus, some of the drying in the first stage may be offloaded to the second stage as the second stage has a lower carbon footprint. Less wood product 106 may be fed to the gasifier as well. During the night when the solar air heaters are less efficient (for example when the solar air heaters are running off of stored energy and when the ambient air has a less favorable temperature and RH relative to ambient air during the day), the first stage may process additional wood product so that during the day (when the ambient temperature is higher and the ambient relative humidity is lower), the second stage has more volume to dry. Adjustments by the control system 170 may also be made throughout the drying process based on the RH of the environment and the intermediate MC of the incoming wood product 102.

[0063] In an example of the control process, 2000 dry kg / hour of wood product 102 is input into the system. The dry weight of the wood product 102 is the weight of the wood product 102 if the moisture contained in the wood product 102 is ignored. In thisexample, the initial MC is 40%. RH and temperature are within a typical range and there is no expected change in either. The control model sets the initial settings to where the Stage 1 dryer 120 is expected to reduce the MC from 40% to 20% and the Stage 2 dryer 130 is expected to further reduce the MC from 20% to 10%. The gasifier-based generator 140 consume 20% of the dry matter flow per day. In this setup there are 34 gasifiers operating at 11.8 dry kg / hour per generator. In addition, each of the 5 briquetting machines are operating at 400 dry kg / hour. The system includes a number of batteries that are used to store excess electricity, for example 10% of combined electrical output, with 90% of the generated electricity used to run the briquetting machine and dryer(s). The control model computes or determines several variables that are used to control the process. These may include one or more of the following variables:A = Initial gross tons CO2e stored in the form of dried briquettes (tons / hr), B = Initial CO2e emissions produced by the process (tons / hr),C = Initial net tons CO2e stored in the form of dried briquettes (tons / hr) where C = A - B, D = Initial cost to run process, ($ / hr), andX = Initial cost per net ton CO2e stored by the process = $X / ton CO2e / hr; where X = D divided by C.

[0064] During the drying process, one or more variables may change or be determined. At an initial stage, the system is operating at a steady state at a cost of $X / ton CO2e / hr as calculated above. In one scenario, the humidity changes over a period of time, for example, as a weather front moves in with precipitation, clouds, and higher humidity. The change in weather may directly affect the drying process by extending the time to dry for the wood product. In addition, the cloud coverage / precipitation may limit or diminish the electricity and / or heated air provided to the solar powered dryers. Accordingly, the Stage 2 dryers 130 (solar powered) become less efficient due to the higher ambient RH and may need to be shut down during precipitation events and / or when the RH exceeds a certain % (e.g., 90%). Renewable electricity and heat production will drop. A change in the drying process may need to be effected by the control model if the system is expected to maintain the current dry matter throughput rate at the previous final MC % target. The control model may enact one or more changes. Power from the batteries may be used to boost the performance of the Stage 2 dryer 130. This response may be limited by the capacity / status of the batteries. The control model may boost the performance of theStage 1 dryer 120, by specifying that more dried wood fuel is burned from a stockpile, by consuming additional non-wood fuel, or by increasing the percentage of the dry matter flow that is diverted to power the gasifier-based generator 140. The control model may combine these responses or seek out alternative solutions. Additional Stage 2 dryers 130 may be used to maintain the throughput. If ten dryers were previously used but now take twice as long to dry, an additional ten dryers may be used to maintain the rate of the processed wood product. Additional airflow may be used in the Stage 2 dryers 130. The use of additional airflow may require additional electricity. Alternatively, the control model may determine that a higher MC is acceptable and may thus do nothing. Finally, the system may leave the parameters and settings of the drying stages unchanged and instead reduce the input flow rate of wood product (so that the final MC % of the wood product does not change).

[0065] The control model is configured to consider the constraints of the system in terms of possible responses (i.e., available fuel; battery capacity; additional Stage 2 dryers 130), to consider the effect of each possible response on the $ / ton CO2e cost, to consider the second-order effects of each possible response on the other possible responses, and to then reach a conclusion regarding the response or responses that minimize the negative effects on the dollars per net ton CO2e removed cost. In one possible outcome of the scenario described above, the control model may (1) draw power from the batteries to boost the performance of the Stage 2 dryer and / or (2) boost the performance of the Stage 1 dryer, and / or (3) bring additional Stage 2 dryers online.

[0066] Other scenarios that would trigger one or more responses from the control system may include an increase (or decrease) in the average MC of the incoming wood product 102; a change in weather resulting in higher temperatures, lower RH, and / or increased renewable energy production; unexpected maintenance downtime for a Stage 1 dryer 120; and / or an unexpected decrease (or increase) in the dry matter flowrate (assuming no change in initial MC %), among other issues. Dry matter refers to that portion of the lignocellulosic biomass that is comprised only of tissues of the plant itself, such as lignin, cellulose, and hemicellulose, and excludes any moisture present within the lignocellulosic biomass.

[0067] As described above, the briquetting machine 160 presses or otherwise shapes the dried wood product 106 into a predetermined shape such as by using a die or mold underhigh pressure. The heat generated during the pressing process, due to friction, allows the lignin component of the wood product to more effectively bind the pressed wood product material. The resulting briquettes 114 are dimensionally stable and ready for storage.

[0068] At act A130, the dried wood product 114 is stored, for example in an aboveground structure / container. The container is designed to prevent intrusion by water, insects, and other stressors that may lead to or promote decomposition of the stored wood product. The container further allows for measurements of the conditions inside the container (e.g., temperature, humidity, and gas composition), allows for airflow (e.g., to complete the drying process if briquettes exceeding 12% in MC are loaded into the storage container), allows for drainage (to remove any water that does intrude), allows for flooding with water or inert gas (to extinguish any fire), and is made of materials that are both fire- resistant and sufficiently durable to withstand weather and other natural events (e.g., earthquakes and high wind) for at least 100 years with minimal maintenance. Once the container is filled with dried wood product 114 and sealed shut, the dried wood product 114 inside the container is expected to remain dry and safe from insects and fire indefinitely (thus avoiding any decomposition of the wood), without the need for any additional intervention beyond regular maintenance.

[0069] In an embodiment, the wood product may first be stored in the container and then dried to a determined MC while being stored in the container. In addition, the wood product may be partially dried, stored, and then dried further in the container. A first drying stage may remove a certain amount of moisture. The wood product may then be stored in the container, for example after being densified or formed into briquettes. A second drying stage may be implemented inside the container using similar mechanisms as described above such as forced air and / or heat. The second drying stage may remove a certain amount of moisture and then be finished. Alternatively, the second drying stage may be continuously or selectively performed as time passes and moisture potentially returns to the previously dried wood product. In one example, a drying module may be moved from container to container to remove additional moisture initially and then when required over time to maintain a predetermined MC level at which the stored wood product will not decompose as a result of microbial or fungal activity.

[0070] Figure 4 depicts an example of a structure / container for storing the dried wood product. In an embodiment, the container is made from regularly sized panels of fiber-reinforced plastic (FRP) and / or any other suitable material that are bolted and / or fastened together to create a larger composite structure. The container may be modular (i.e., constructed from many replicates of similar or identical component parts), with component panels made from either the same or different materials and bolted and / or fastened together to create a single container. One or more sealant materials may be applied to the seams between panels and / or may be placed between the panels that are bolted and / or fastened together to make the container more watertight. A modular construction may allow for different configurations depending on the environmental conditions and need for space. Modular construction, for example, allows for differently sized containers / structures to be used. Panels that measure 1 meter x 1 meter in external surface area can be used to create containers with footprints having different sizes and shapes, for example, a 10m x 10m structure, or a 100m x 100m structure etc., each with any height that does not detract from the necessary stability of the entire structure. For example, as shown in Figure 4, each stack of materials may be five or more meters tall. For convenience, the footprint of each stack of materials may be approximately 1 meter x 1 meter where hundreds or thousands or more such stacks may be stored in one larger storage container.

[0071] The construction of the container may or may not include internal walls. Loading the stacks of wood product into the container may be easier without internal walls or supports. A roofing support structure may be used as described below in place of internal supports. A foundation may be provided that may be configured to drain or otherwise remove moisture from the interior of the container. The bottom of each stack or the foundation may include a porous material such as crushed rock that allows water to pool in the bottom of the foundation / stack and may also inhibit the diffusion of the pooled water upward into the stacks of wood product. Thus, the bottom may provide a separate place for any water in the system to accumulate away from the stored material, so that the water can be removed or drain out later. The floor of the container structure may or may not be comprised of the same panels as the sides and roof of the structure, or may be absent entirely, or may be comprised of a different material such as asphalt or concrete. A pump, valve, airflow, or other mechanism may be used to remove any accumulated water. The outside walls and roof may be constructed from similar modular panels of FRP or any other suitable material or combination of materials. The roof may be supported byinternal walls or supports or by the stacks of materials (especially wood product) as described below and in Figures 5-7.

[0072] In an embodiment, the briquettes 114 may be stacked or otherwise grouped to match the panel sizes. The units of stacked briquettes (e.g., pallets) may themselves be stacked directly one on top of the other, or may be stacked such that adjacent layers of pallets are offset horizontally such that each pallet is staggered rather than stacked directly on top of the pallet directly underneath. In an embodiment, the pallets overlap one another by 25%, 33%, or 50%. Partial pallets or additional material may be used to support overlapping pallets. The overlapping of the pallets increases the stability of the entire mass of stacked pallets within the storage container. In another embodiment, the pallets may be stacked in a pyramidal shape where the area of the base is larger than the area of the top of the pallet stack. Storage containers that are constructed using modular panels may also be easier to build and maintain, because a panel may be more easily replaced or repaired if it fails. In addition to ruggedness / durability over a long period of time, there are numerous other characteristics that the container may have, including but not limited to resistance to water intrusion and the ability to withstand seismic events, ultraviolet (UV) radiation, wind, frequent temperature cycling, and contact with the extractive compounds present in wood waste. In an embodiment, the solutions to these problems may be targeted (such as a surface coating to protect the container panels from UV radiation and / or a special foundation to handle seismic events), or the solutions may be more general (such as designing the containers to allow for regular maintenance).

[0073] One issue with modular construction is that the larger the physical footprint of a structure / container gets, the larger the distance that the roof must span, necessitating structural support to prevent the roof from sagging or collapsing. Internal supports or joists complicate the construction of the container and the loading of the material(s) to be stored / contained therein. Internal supports or joists also take up space which could otherwise be used to store more material(s). Internal walls further increase the amount of material(s) needed for the container. With joists that span the exterior walls, the load of the roof is transferred to the walls of the container which then are required to be more robust. The required size and load-bearing features of the joists change as the distance that the joists must cover changes, further complicating the design and construction of the container.

[0074] In an embodiment, the dried wood product 114 that is stored in the modular container / structure is used to hold up or at least partially support the weight of the roof. The briquettes 114 may be stacked, for example, on a pallet or similar base. One or more of the plurality of stacks of briquettes 114 are configured to transfer at least a portion of the weight of the roof to the base and / or walls of the container and / or to a foundation on which the container rests.

[0075] In a first roofing support embodiment, each stack that is used as a support is wrapped using a rigid material such as plywood that stabilizes the wrapped stack so that it can transfer the weight of the roof to the foundation without destabilizing neighboring stacks of wood product 501. Figure 5 depicts an example of such a system where one stack is wrapped in plywood to make the wrapped stack a more stable support column for the roof. Figure 5 depicts a container with 81 stacks of wood product 501 in a 9 x 9 grid. Four of the stacks of wood product 501 are wrapped in a rigid material (here, plywood) and are used as ply wood- wrapped columns 503. As shown in Figure 5, the container / structure may be further reinforced by connecting additional interior walls to the columns 503, so that the load of the roof is partially supported by the interior and exterior walls as well as by the base and foundation of the container / structure. Not all stacks are used as support columns 503. The columns 503 may be spaced at regular intervals (as columns would be in an ordinary structure).

[0076] In a second roofing support embodiment, the weight of the roof is transferred though the stacked wood product where certain stacks are each connected to the roof using a mechanism (such as a jack) extending between the lower surface of the roof and an upper surface of the stack and configured to transfer at least a portion of the load of the roof to the stack. The roof may or may not be sloped. Figures 6A and 6B depict examples where there are four stacks of wood product 501 with one stack having a “jack” 507, 509 on top that supports the roof 505. Figure 6A depicts a vertical thread “screw” jack 509. Figure 6B depicts a scissor jack 507. Any type of jack or other support mechanism may be used as long as it provides a variable and controllable height so that stacks with different heights may support different areas of the roof 505, and so that the height of the jack or other support mechanism may be adjusted (whether automatically and / or passively or manually) in the future if the height of the stack of wood product increases or decreases for any reason.

[0077] In a third roofing support embodiment, the weight of the roof is transferred through the stacked wood product where certain stacks are each connected to the roof using a wedge assembly. Figures 7A and 7B depict side views of a container where there is a single stack of wood product 501 and where there are four stacks of wood product 501 that use one or more wedge assemblies 511 to support the roof 505. In an embodiment, the wedge assembly 511 is configured as a system of three wedges including a top wedge 513 that is in contact with the roof of the container, a middle wedge 515 (to which a restoring force F is applied by a compressed spring mechanism 519 to prevent slippage of the middle wedge 515 in a direction that would tend to decrease the support of the roof and thus encourage the lowering of the elevation of the roof), and a bottom wedge 517 that rests on the top of a stack of wood product. The restoring force F may include any mechanism, such as a compressed spring mechanism 519, which counteracts the tendency of the middle wedge 515 to be forced out of the wedge assembly as a result of the compression of the top wedge by the roof, thereby causing excessive counteracting force in a direction opposite to that of the restoring force F. Furthermore, the restoring force F may be such that the middle wedge 515 moves laterally between the top wedge 513 and the bottom wedge 517 in the event that the stack of wood product begins to settle to a lower elevation. The function of the restoring force F in this embodiment is to cause the middle wedge 515 to move laterally in response to a decrease in the elevation of the top of the stack of wood product, such that direct contact is maintained between the three wedges and the resulting increase in distance between the top of wedge 513 and the bottom of wedge 517 just offsets the decrease in elevation of the top of the stack of wood product. Differently sized or shaped wedges may be used. The wedges also need not be triangular in shape. For example, the bottom wedge 517 may have the cross-sectional shape of a quadrilateral in which two sides are parallel to one another and the other two sides are not parallel to one another, and for which one of the two non-parallel sides will appear to be slanted when the opposite side rests on a flat surface. The restoring force F may be supplied by a compressed spring mechanism 519 that expands to push the wedge toward the left (i.e. , toward the edge of the container in Figure 7A) if the top of the stacked wood product 501 settles to a lower elevation. The spring of the compressed spring mechanism 519 stops expanding when the frictionalforces acting on the wedge, due to the direct contact between the wedge and the surfaces of the roof and wood product, balance the applied force F.

[0078] In Figure 7B there are two stacks that include wedge assemblies 511 that are sized differently for the respective slope of the roof 505 and position of the stacked wood product 501. As depicted in Figures 7A and 7B each wedge assembly 511 includes a middle wedge 515 that is placed and held between the top wedge 513 and the bottom wedge 517 so that the roof 505 is supported by the stack of wood product 501 that is located under the wedge assembly 511. In addition, as in Figure 7A, a mechanism, such as a compressed spring 519 providing the restoring force F (as discussed above) may be implemented to counteract the tendency of the middle wedge 515 to be forced out of its initial position in a manner that would encourage the elevation of the roof to change. This mechanism functions in a way that moves the middle wedge 515 in a direction that maintains support of the roof by the top wedge should the elevation of the top of the stack of wood product change. Any type of wedge may be used to make the wedge assembly 511 as long as the wedge assembly 511 transfers at least a portion of the weight of the roof to the stacked wood product.

[0079] Another challenging aspect of the modular construction of the structure / container is the base. Once the container is assembled and filled with wood product, it may be necessary to repair or otherwise access the foundation and / or the floor and / or the modular base panels (which may or may not provide the entire floor of the structure / container) and / or the fasteners (that hold the base panels together) and / or the seals (that prevent water from entering through the base). In addition, any water that may leak into the container may accumulate in and around the base panels, so it may be more efficient to remove water through the base of the container. Previous designs for modular containers have addressed these challenging aspects of the base by elevating the container / structure on flat concrete plinths. If modular panels are employed to construct the base of the container, instead of resting the stacks of wood product directly on the floor / foundation, then elevating the container’s base above the ground allows workers to access the base panels, the seals between them, and the fasteners that hold them together, and also allows for water to be drained through the base whenever necessary. The disadvantage of elevating the container’s base above the ground is the high cost of the concrete plinths and of the additional concrete foundation that must support the concrete plinths, includingthe C02 emissions resulting from the production of the necessary concrete. The frequent use of additional steel beams to support the modular structure / container on top of the concrete plinths adds further costs and process CO2 emissions.

[0080] In an embodiment, the modular panels may or may not be used for the base of the container, or the modular panels may provide only part of base of the container / structure (for example, at the edges). The container walls and roof may rest directly on the container’s floor / foundation and the stacks of densified wood product may then be arranged on top of the foundation, or whatever modular panels and / or floor surface are under the container walls and roof, in order to support the wood product as well as the weight of the container walls and roof. The container may have 5 sides and no bottom or only a partial bottom, where the foundation itself serves as the full or partial bottom.

[0081] Figures 8 and 9 depict views of an embodiment of a container base. The modular base panels 814 may have a convex pyramid- like polygon shape and / or a convex curvature and are therefore referred to as convex base panels 814. Alternative shapes may be used for the modular base panels 814. In Figures 8 and 9, the edges of the convex base panels 814 are not connected to each other with fasteners; instead, a grating 816 is attached to the top of the convex modular base panels 814, such as with fasteners, wherein the stored wood product in the form of compressed wood briquettes 114 is placed on top of this grating 816 and may also be placed on top of pallets 810. In addition, the convex base panels 814 do not need to sit on top of concrete plinths and / or steel beams. Instead, the convex base panels 814 may sit directly on a less expensive foundation 812, such as gravel or asphalt, which also reduces the CO2 footprint of the foundation 812 compared to concrete. There may also be no need for fasteners or sealant 820 located directly between the seams of the convex base panels 814, because each section of grating 816 can be fastened to the tops of multiple convex base panels 814, thereby connecting the convex base panels 814 to one another and holding them in place. In addition, the top of each convex base panel 814 may be fastened to multiple pieces / sections of grating 816, which allows the grating 816 to be modular. Furthermore, the weight of the stored wood product 114 resting on the tops of the convex base panels 814 transfers force to the edges of the base panels 814, thus improving the seals between the seams of adjacent convex base panels 814. The stored wood product 114 is also kept elevated by the convex basepanels 814 and by the grating 816 underneath them, thereby reducing the risk that water may intrude through seams and reach the stored wood product.

[0082] Figures 10 and 11 depict another embodiment of the container base. As before, the modular base panels 814 may have a convex pyramid-like polygon shape and / or a convex curvature and are therefore referred to as convex base panels 814. In addition, the drainage panels 832 may have a concave polygon shape and / or a concave curvature and thus may also be referred to as concave drainage panels 832. In Figures 10 and 11 the tops of the convex base panels 814 are connected to a grating 816 with fasteners such as a bolt assembly 818, and the convex base panels 814 are also connected to concave drainage panels 832 at regular intervals, wherein the stored wood product 114 is placed on top of this grating 816 and may also be placed on top of pallets 810. Fasteners may or may not be used for the connections between the seams of the convex base panels 814. However, fasteners and a bolt / hinge assembly 834 may be used to connect the convex base panels 814 and concave drainage panels 832, respectively, as the concave drainage panel 832 lacks an elevated point at the plane of the grating material. In this implementation, the sections of grating 816 that span one or more concave drainage panels 832 may attach to adjacent or nearby base panels 814. As shown in Figures 10 and 11, the fasteners may attach to a bolt / hinge assembly 834 that serves to connect the concave drainage panel 832 to adjacent convex base panels 814. Due to its flexibility, the bolt / hinge assembly 834 also allows the base panels 814 and concave drainage panels 832 to tolerate a slightly uneven surface underneath them and reduces the likelihood of damage to the panels 814, 832 that could result if the ground settles over time. This embodiment keeps the stored wood product 114 elevated and reduces the probability that water that may enter through the seams between the base panels 814 will reach the stored wood product 114. In addition, as shown in Figures 10 and 11, water that may leak into the container through the roof or sides passes through the grating 816 and reach the base panels 814. Arrows show the direction of water flow. This embodiment channels water away from the convex modular base panels 814 and towards the concave drainage panels 832 so that the water can drain out of the container.

[0083] Figures 12 and 13 depict another embodiment where a grating 816 is not used. The flat top of each convex modular base panel 814 has a surface area that is sufficiently large to allow aggregates of the stored wood product 114 on a pallet 810 having a flat base torest directly on top of the convex base panels 814. In this embodiment, both the convex base panels 814 and the concave modular drainage panels 832 are connected to each other with fasteners that attach to a bolt / hinge assembly 818 and 834. As with the other embodiments, this embodiment keeps the stored wood product 114 elevated relative to the bottoms of the convex base panels 814 and also channels water toward the concave drainage panels 832 so that the water may drain out of the container, e.g., through a drain opening 830. Arrows show the direction of water flow.

[0084] Yet another challenging aspect of the modular construction of the structure / container is the seam between each adjacent pair of modular panels. As shown in Figures 14 and 15, the roof panels 910 are shaped so that water flows along the inter-panel seams from the center of the roof toward the edges of the roof, where it then flows down the side panels 824 toward the ground. Arrows show the direction of water flow. For the container to resist water intrusion (from rainfall or even from daily condensation), a sealant material is typically placed between each pair of modular panels, and the panels are then bolted and / or fastened together to form a watertight seal. This approach to making the seams of the modular container watertight works for as long as the sealant material remains undamaged. However, over time, a variety of factors (including but not limited to temperature cycling, the pressure between the panels, and periodic wetting and drying) may cause the sealant material to crack and / or flake and eventually fail to form a watertight seal. Thus, over hundreds of years, a significant number of seams, especially on the roof, may fail and begin to allow water to leak into the container. This water intrusion can be stopped by dis-assembling the modular roof panels and replacing the sealant material, thus restoring the watertight seal in each affected inter-panel seam, but that solution greatly increases the cost per net ton of CO2e stored in the form of dried and densified wood product inside the container.

[0085] Figure 16 depicts an example of a water drainage system for the container roof. Arrows show the direction of water flow. In Figure 16, a J-shaped attachment 912 is attached to parallel edges of a roof panel 910 using the same bolts and / or fasteners that connect the modular roof panel to the adjacent modular roof panels. The J-shaped attachments 912 are placed so that the troughs of the attachments are beneath parallel seams between the roof panels 910, e.g., forming a gutter to collect water which may get through the seam above. As depicted in Figure 17, W-shaped attachments 914 may beattached to the edges of the modular roof panels 910 (using the same bolts and / or fasteners that connect the modular roof panel to the adjacent modular roof panels), such that the W-shaped attachments 914 are perpendicular to the J-shaped attachments. The W- shaped attachments 914 are placed so that their troughs are beneath parallel seams between the modular roof panels 910 and below the troughs of the J-shaped attachments 912.

[0086] In the embodiment shown in Figures 16 and 17, water that may leak through the seams between the roof panels 910 is collected in the troughs of the J-shaped 912 and W- shaped attachments 914. Water that is collected by a J-shaped attachment 912 may flow until the J-shaped 912 attachment intersects a W-shaped attachment 914. Because the W- shaped attachment 914 is below the J-shaped attachment 912, the water in the J-shaped attachment 912 may flow into the W-shaped attachment 914. As shown in Figure 18, the water collected by the W-shaped attachments 914 (and by J-shaped attachments 912 that do not intersect a W-shaped attachment 914) may flow until the W-shaped 914 and J- shaped 912 attachments reach either a side of the container or one or more hollow roof support pipes 916. The roof support pipe 916 may be shaped so that water can flow from the W-shaped attachments 914 and J-shaped attachments 912 into the roof support pipe. Once inside the roof support pipe 916, the water may flow to the bottom of the container. From the bottom of the container, the water may then exit the container without touching the stored wood product 114. The J-shaped attachments 912, W-shaped attachments 914, hollow roof support pipes 916, and the mechanisms for draining water from the sides and bottom of the container therefore prevent any water that may leak into the container from touching the stored wood product 114, and thus prevent any biological decomposition of the stored wood product 114.

[0087] In addition to facilitating the removal of water from the container, the J-shaped attachments 912, W-shaped attachments 914, and roof support pipes 916, when used with water detectors and / or sensors, may make it easier to determine the approximate location of any leak in an inter-panel seam of the container.

[0088] At act A140, the dried wood product 114 is monitored while stored in the container. A monitoring system may monitor at least a humidity level inside the container. The monitoring system may also measure a temperature inside the container and / or the moisture content of at least a portion of the wood product. The monitoring system maymeasure the concentration of CO2 or other gaseous components, such as methane, inside the container or in the vicinity of the container to infer whether the dried wood product may be decomposing at a measurable rate. The monitoring system may be implemented by placing multiple sensors inside the container at different locations. The monitoring system may communicate with the sensors and / or a control panel using wired or wireless communications. The monitoring system may generate alerts when one or more sensors detect conditions that are not consistent with the indefinite storage of the wood product without the loss of dry matter via biological decomposition, chemical reaction, fire, or any other process.

[0089] The term “computer-readable medium” includes a single medium or multiple media, such as a centralized or distributed database, and / or associated caches and servers that store one or more sets of instructions. The term “computer-readable medium” shall also include any medium that is capable of storing, encoding, or carrying a set of instructions for execution by a processor or that cause a computer system to perform any one or more of the methods or operations disclosed herein.

[0090] In a particular non-limiting embodiment, the computer-readable medium may include a solid-state memory such as a memory card or other package that houses one or more nonvolatile read-only memories. Further, the computer-readable medium may be a random access memory or other volatile re-writable memory. Additionally, the computer- readable medium may include a magneto-optical or optical medium, such as a disk or tapes or other storage device to capture carrier wave signals such as a signal communicated over a transmission medium. A digital file attachment to an e-mail or other self-contained information archive or set of archives may be considered a distribution medium that is a tangible storage medium. Accordingly, the disclosure is considered to include any one or more of a computer-readable medium or a distribution medium and other equivalents and successor media, in which data or instructions may be stored.

[0091] In an alternative embodiment, dedicated hardware implementations, such as application specific integrated circuits, programmable logic arrays and other hardware devices, may be constructed to implement one or more of the methods described herein. Applications that may include the apparatus and systems of various embodiments may broadly include a variety of electronic and computer systems. One or more embodiments described herein may implement functions using two or more specific interconnectedhardware modules or devices with related control and data signals that may be communicated between and through the modules, or as portions of an application- specific integrated circuit. Accordingly, the present system encompasses software, firmware, and hardware implementations.

[0092] In accordance with various embodiments of the present disclosure, the methods described herein may be implemented by software programs executable by a computer system. Further, in an exemplary, non-limited embodiment, implementations may include distributed processing, component / object distributed processing, and parallel processing. Alternatively, virtual computer system processing may be constructed to implement one or more of the methods or functionalities as described herein.

[0093] Although the present specification describes components and functions that may be implemented in particular embodiments with reference to particular standards and protocols, the invention is not limited to such standards and protocols. For example, standards for Internet and other packet switched network transmission (e.g., TCP / IP, UDP / IP, HTML, HTTP, HTTPS) represent examples of the state of the art. Such standards are periodically superseded by faster or more efficient equivalents having essentially the same functions. Accordingly, replacement standards and protocols having the same or similar functions as those disclosed herein are considered equivalents thereof.

[0094] A computer program (also known as a program, software, software application, script, or code) may be written in any form of programming language, including compiled or interpreted languages, and it may be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program may be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

[0095] The processes and logic flows described in the specification may be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes andlogic flows may also be performed by, and apparatus may also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0096] As used in the application, the term ‘circuitry’ or ‘circuit’ refers to all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) to combinations of circuits and software (and / or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s) / software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

[0097] This definition of ‘circuitry’ applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term “circuitry” would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and / or firmware. The term “circuitry” would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or other network device.

[0098] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor receives instructions and data from a read only memory or a random-access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer also includes, or is operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer may be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio player, a GPS receiver, to name just a few. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The memory may be a non-transitory medium such as a ROM, RAM, flash memory, etc. The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.

[0099] To provide for interaction with a user, embodiments of the subject matter described in this specification may be implemented on a device having a display, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user may provide input to the computer. Other kinds of devices may be used to provide for interaction with a user as well; for example, feedback provided to the user may be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including acoustic, speech, or tactile input.

[0100] Embodiments of the subject matter described in this specification may be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a Web browser through which a user may interact with an implementation of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system may be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.

[0101] The computing system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client- server relationship to each other.

[0102] The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features ofapparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and may not be drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive.

[0103] While this specification contains many specifics, these should not be construed as limitations on the scope of the invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the invention. Certain features that are described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

[0104] Similarly, while operations are depicted in the drawings and described herein in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described components and systems may generally be integrated together in a single product, process, system, or software product or packaged into multiple products, processes, systems, or software products.

[0105] One or more embodiments of the disclosure may be referred to herein, individually and / or collectively, by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any particularinvention or inventive concept. Moreover, although specific embodiments have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, are apparent to those of skill in the art upon reviewing the description.

[0106] The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.

[0107] It is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is understood that the following claims including all equivalents are intended to define the scope of the invention. The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.

[0108] The following is a list of non-limiting illustrative embodiments disclosed herein:

[0109] Illustrative embodiment 1. A method for producing dried briquettes for long term storage, the method comprising: acquiring wood product with an initial moisture content level; drying, using one or more dryers, the wood product from the initial moisture content level to a second moisture content level; and generating, using one or more briquetting machines, dried wood briquettes from the wood product dried to the second moisture content level; wherein a process control model is used to monitor and adjust one or more parameters for the drying in order to minimize a cost per net ton of CO2e stored in a form of dried wood briquettes.

[0110] Illustrative embodiment 2. The method of illustrative embodiment 1, wherein drying comprises: drying, in a first stage, the wood product from the initial moisture content level to a first moisture content level using a first amount of energy; and drying, in a second stage, the wood product from the first moisture content level to a second moisture content level using a second amount of energy, wherein one of the first or second stages uses at least some of the dried wood product to generate at least a portion of the first or second amounts of energy to dry incoming wood product, wherein the other of the first or second stages uses a renewable energy source to provide at least a portion of the first or second amounts of energy to dry the wood product.

[0111] Illustrative embodiment 3. The method of illustrative embodiment 2, wherein the first stage uses waste heat and electricity from a gasifier-based generator.

[0112] Illustrative embodiment 4. The method of illustrative embodiment 3, wherein the gasifier-based generator uses at least some of the wood product dried to the second moisture content level as an energy source.

[0113] Illustrative embodiment 5. The method of illustrative embodiment 2, wherein the second stage uses heat and / or energy derived from a renewable source.

[0114] Illustrative embodiment 6. The method of illustrative embodiment 2, wherein the one or more parameters comprise one or more of electrical power for a fan or dryer, a temperature and a humidity of a drying environment, the initial moisture content level, the second moisture content level, a volume of air flow, an on / off status of a fan, a rate of heat supplied to ambient air, a temperature and a humidity of ambient air, and / or a percentage of wood product that is gasified to produce electricity and waste heat for drying.

[0115] Illustrative embodiment 7. The method of illustrative embodiment 1, wherein the process control model is configured to minimize a dollar cost per net ton of CO2e stored in the form of dried wood briquettes by maximizing an output of dried wood briquettes and minimizing a cost of inputs to the one or more dryers and the one or more briquetting machines.

[0116] Illustrative embodiment 8. The method of illustrative embodiment 1, further comprising: storing the dried wood briquettes in a container configured to store and monitor the dried wood briquettes.

[0117] Illustrative embodiment 9, The method of illustrative embodiment 8, wherein the units of dried wood briquettes (e.g., pallets) are stacked such that adjacent layers of units / pallets are offset horizontally by a certain proportion, which may be adjustable and based on the implementation, such that each pallet is staggered rather than stacked directly on top of the pallet(s) directly underneath it.

[0118] Illustrative embodiment 10. The method of illustrative embodiment 8, wherein the container includes a roofing support structure where the dried wood briquettes that are stored in the container are used to hold up or support at least partially a weight of a roof of the container.

[0119] Illustrative embodiment 11. A system producing dried wood briquettes for long term storage, the system comprising: a first stage dryer configured to dry wood product from an initial moisture content level to a first moisture content level; a second stage dryer configured to dry the wood product from the first moisture content level to a second moisture content level; a briquetting machine configured to generate dried wood briquettes from the wood product with the second moisture content level; and a control system configured to adjust one or more parameters of the first stage dryer and second stage dryer in order to minimize a dollar cost per net ton of CO2-equivalent stored in a form of dried wood briquettes.

[0120] Illustrative embodiment 12. The system of illustrative embodiment 11, further comprising: a gasifier-based generator configured to provide waste heat and electricity to one of the first or second stage dryer.

[0121] Illustrative embodiment 13. The system of illustrative embodiment 12, wherein the gasifier-based generator uses at least some of the wood product dried to the second moisture content level as an energy source.

[0122] Illustrative embodiment 14. The system of illustrative embodiment 11, further comprising: a renewable power source configured to provide heat, electricity, or heat and electricity to one of the first or second stage dryer.

[0123] Illustrative embodiment 15. The system of illustrative embodiment 11, further comprising: a long-term storage container constructed from modular fiber reinforced plastic (FRP) panels, wherein the long-term storage container is configured to prevent decomposition of the stored dried wood briquettes.

[0124] Illustrative embodiment 16. The system of illustrative embodiment 15, wherein the units of dried wood briquettes (e.g., pallets) are stacked such that adjacent layers of units / pallets are offset horizontally by a certain proportion, which may be adjustable and based on the implementation, such that each pallet is staggered rather than stacked directly on top of the pallet(s) directly underneath it.

[0125] Illustrative embodiment 17. The system of illustrative embodiment 15, wherein the long-term storage container includes a roofing support structure where the dried wood briquettes that are stored in the long-term storage container are used to hold up or support at least partially a weight of a roof of the long-term storage container.

[0126] Illustrative embodiment 18. A container for storing dried wood product, the container comprising: a plurality of walls and a roof constructed from modular panels; a base constructed from modular panels; and a roofing support system in which the dried wood product that is stored in the container is used to hold up or support at least partially a weight of the roof of the container, wherein the container is configured to keep out water and insects in order to prevent decomposition and / or infestation of the stored dried wood product.

[0127] Illustrative embodiment 19. The container of illustrative embodiment 18, wherein the modular panels provide less than the entire base of the container, and the remainder of the base of the container is provided by the foundation and / or another floor surface.

[0128] Illustrative embodiment 20. The container of illustrative embodiment 18, further comprising: a monitoring system configured to monitor at least a humidity level inside the container.

[0129] Illustrative embodiment 21. The container of illustrative embodiment 18, wherein one or more dryers and / or fans further dry the stored wood product while it is inside the container.

[0130] Illustrative embodiment 22. The container of illustrative embodiment 18, wherein the roofing support system comprises one or more jacks installed on a top of a stack of the dried wood product, wherein the one or more jacks transfer at least partially the weight of the roof to the stack of the dried wood product.

[0131] Illustrative embodiment 23. The container of illustrative embodiment 18, wherein the roofing support system comprises a wedge assembly comprising one or more wedges and a mechanism for applying a restoring force to one or more wedges of the assembly.The wedge assembly and the mechanism used to apply the restoring force are installed on a top of a stack of the dried wood product, wherein the wedge assembly transfers at least partially the weight of the roof to the stack of the dried wood product.

[0132] Illustrative embodiment 24. The container of illustrative embodiment 18, wherein the roofing support system comprises one or more support columns each comprising a stack of the dried wood product wrapped in a rigid material.

[0133] Illustrative embodiment 25. The container of illustrative embodiment 24, wherein each of the one or more support columns is connected to one or more of a plurality of exterior walls by additional interior walls to reinforce a structural integrity of the container.

[0134] Illustrative embodiment 26. A container for storing dried wood product, the container comprising: a plurality of walls constructed from modular side panels; a roof constructed from a plurality of modular roof panels; and a base structure constructed from a plurality of modular base panels and a plurality of modular drainage panels; wherein the container is configured to keep out water and insects in order to prevent decomposition and / or infestation of the stored dried wood product.

[0135] Illustrative embodiment 27. The container of illustrative embodiment 26, wherein the plurality of modular base panels are convex shaped, wherein the plurality of modular drainage panels are concave shaped.

[0136] Illustrative embodiment 28. The container of illustrative embodiment 26, wherein the base structure further comprises a grating that is attached to a top of each modular base panel of the plurality of modular base panels, and the edges of each of the modular base panels are not connected to each other with fasteners.

[0137] Illustrative embodiment 29. The container of illustrative embodiment 26, wherein the plurality of modular drainage panels are configured to direct water from the base structure to a drain opening.

[0138] Illustrative embodiment 30. The container of illustrative embodiment 26, wherein the plurality of modular base panels are connected to the plurality of modular drainage panels with fasteners that attach to a bolt / hinge assembly.

[0139] Illustrative embodiment 31. The container of illustrative embodiment 26, wherein fasteners that attach to a bolt / hinge assembly are used to connect the plurality of modular base panels and the plurality of modular drainage panels, and wherein a flat top of each ofthe plurality of modular base panels includes a surface area that is sufficiently large to allow the dried wood product having a flat base to rest directly on top of the plurality of modular base panels.

[0140] Illustrative embodiment 32. The container of illustrative embodiment 26, further comprising a roof drainage system comprising J-shaped attachments attached to edges of the plurality of modular roof panels using fasteners that connect adjacent modular roof panels of the plurality of modular roof panels such that troughs of the J-shaped attachments are beneath seams between the plurality of modular roof panels.

[0141] Illustrative embodiment 33. The container of illustrative embodiment 32, wherein the roof drainage system further comprises: W-shaped attachments that are attached to edges of the plurality of modular roof panels such that the W-shaped attachments are perpendicular to the J-shaped attachments, and such that troughs of the W-shaped attachments are beneath seams between the modular roof panels, and also below the troughs of the J-shaped attachments.

[0142] Illustrative embodiment 34. The container of illustrative embodiment 33, wherein the roof drainage system further comprises hollow roof support pipes that are configured so that water flows from the W-shaped attachments and the J-shaped attachments into the roof support pipes and toward the base of the container.

Claims

CLAIMS1. A system for storing dried wood product comprising: a container configured to store dried wood product, the container comprising: a plurality of walls and a roof constructed from modular panels; a base comprising modular panels, a foundation, or modular panels and the foundation; and a roofing support system in which the dried wood product that is stored in the container is used to hold up or support at least partially a weight of the roof of the container; wherein the container is configured to keep out water and insects in order to prevent decomposition and / or infestation of the dried wood product.

2. The system of claim 1, further comprising: one or more dryers, one or more fans, or one or more dryers and one or more fans configured to dry stored wood product inside the container; and a monitoring system configured to monitor at least a humidity level inside the container.

3. The system of claim 1, wherein the roofing support system comprises one or more jacks installed on a top of a stack of the dried wood product, wherein the one or more jacks transfer at least partially the weight of the roof to the stack of the dried wood product.

4. The system of claim 1, wherein the roofing support system comprises a wedge assembly comprising one or more wedges and a mechanism for applying a restoring force to one or more wedges of the wedge assembly, wherein the wedge assembly and the mechanism are installed on a top of a stack of the dried wood product, wherein the wedge assembly transfers at least partially the weight of the roof to the stack of the dried wood product.

5. The system of claim 1, wherein the roofing support system comprises one or more support columns each comprising a stack of the dried wood product wrapped in a rigid material.

6. The system of claim 5, wherein each of the one or more support columns is connected to one or more of a plurality of exterior walls by one or more additional interior walls that are configured to reinforce a structural integrity of the container.

7. The system of claim 1, further comprising: a first stage dryer configured to dry wood product from an initial moisture content level to a first moisture content level; a second stage dryer configured to dry the wood product from the first moisture content level to a second moisture content level; a briquetting machine configured to generate dried wood briquettes from the wood product with the second moisture content level; and a control system configured to adjust one or more parameters of the first stage dryer and second stage dryer in order to minimize a dollar cost per net ton of CO2- equivalent stored in a form of dried wood briquettes; wherein the dried wood briquettes are stored in the container and stacked such that adjacent layers of the dried wood briquettes are offset horizontally such that each respective layer is staggered with respect to layers directly beneath and above the respective layer.

8. The system of claim 7, wherein a gasifier-based generator configured to provide waste heat and electricity to one of the first stage dryer or the second stage dryer.

9. The system of claim 8, wherein the gasifier-based generator uses at least some of the wood product dried to the second moisture content level as an energy source.

10. The system of claim 7, further comprising: a renewable power source configured to provide heat, electricity, or heat and electricity to one of the first or second stage dryer.

11. A container for storing dried wood product, the container comprising: a plurality of walls constructed from modular side panels; a roof constructed from a plurality of modular roof panels; and a base structure constructed from a plurality of modular base panels and a plurality of modular drainage panels; wherein the container is configured to keep out water and insects in order to prevent decomposition and / or infestation of the stored dried wood product.

12. The container of claim 11, wherein the plurality of modular base panels are convex shaped, wherein the plurality of modular drainage panels are concave shaped.

13. The container of claim 11, wherein the base structure further comprises a grating that is attached to a top of each modular base panel of the plurality of modular base panels, and edges of each of the modular base panels are not connected to each other with fasteners.

14. The container of claim 11, wherein the plurality of modular drainage panels are configured to direct water from the base structure to a drain opening.

15. The container of claim 11, wherein the plurality of modular base panels are connected to the plurality of modular drainage panels with fasteners that attach to a bolt and hinge assembly.

16. The container of claim 11, wherein fasteners that attach to a bolt and hinge assembly are used to connect the plurality of modular base panels and the plurality of modular drainage panels, and wherein a flat top of each of the plurality of modular base panels includes a surface area that is sufficiently large to allow the dried wood product having a flat base to rest directly on top of the plurality of modular base panels.

17. The container of claim 11, further comprising a roof drainage system comprising J-shaped attachments attached to edges of the plurality of modular roof panels using fasteners that connect adjacent modular roof panels of the plurality of modular roof panels such that troughs of the J-shaped attachments are beneath seams between the plurality of modular roof panels.

18. The container of claim 17, wherein the roof drainage system further comprises: W- shaped attachments that are attached to edges of the plurality of modular roof panels such that the W-shaped attachments are perpendicular to the J-shaped attachments, and such that troughs of the W-shaped attachments are beneath seams between the modular roof panels and below the troughs of the J-shaped attachments.

19. The container of claim 18, wherein the roof drainage system further comprises hollow roof support pipes that are configured so that water flows from the W-shaped attachments and the J-shaped attachments into the hollow roof support pipes and toward the base structure of the container.

20. A method for constructing a container for storing dried wood product, the method comprising: acquiring a plurality of modular panels including a plurality of modular side panels, a plurality of modular roof panels, a plurality of modular drainage panels, and a plurality of modular base panels; constructing a base of the container where the plurality of modular base panels are convex shaped, wherein the plurality of modular drainage panels are concave shaped;constructing sides of the container using the plurality of modular side panels; and constructing a roof of the container using the plurality of modular roof panels, wherein the container includes a roof drainage system comprising J-shaped attachments attached to edges of the plurality of modular roof panels using fasteners that connect adjacent modular roof panels of the plurality of modular roof panels such that troughs of the J-shaped attachments are beneath seams between the plurality of modular roof panels