Method of carbon sequestering

Abstract

A method of sequestering carbon captured from the atmosphere by plants (biomass) waste material includes segregating incoming waste material that includes biomass into high-moisture incoming waste material and low-moisture incoming waste material. The low-moisture incoming waste material is that which has a moisture content less than or equal to the moisture content threshold, for example, paper, cardboard, and sawdust. The low-moisture incoming waste material is stored in a dry containment area, thereby emissions of carbon dioxide or methane from the low-moisture incoming waste material is reduced as moisture is required by such material to decompose.

Claims

1. A method of sequestering carbon-based material, the method comprising: segregating incoming carbon-based material into high-moisture incoming carbon-based material and low-moisture incoming carbon-based material, the high-moisture incoming carbon-based material having a moisture content greater than a moisture content threshold and the low-moisture incoming carbon-based material having a moisture content less than or equal to the moisture content threshold; and storing the low-moisture incoming carbon-based material in a dry containment area, thereby emissions of carbon dioxide or methane from the low-moisture incoming carbon-based material is reduced or eliminated.

2. The method of claim 1, wherein the dry containment area maintains the low-moisture incoming carbon-based material at a moisture content less than or equal to the moisture content threshold.

3. The method of claim 1, further comprising sorting the high-moisture incoming carbon-based material into high-moisture carbon-based material and remaining low-moisture carbon-based material, the remaining low-moisture carbon-based material having the moisture content that is less than the moisture content threshold, and storing the remaining low-moisture carbon-based material in the dry containment area.

4. The method of claim 3, further comprising drying the high-moisture carbon-based material into carbon-based material that has a moisture content that is less than the moisture content threshold and storing a carbon-based material that has been dried in the dry containment area.

5. The method of claim 1, further comprising drying the high-moisture incoming carbon-based material to have the moisture content that is less than a moisture content threshold and storing resulting carbon-based material that has been dried in the dry containment area.

6. The method of claim 1, wherein the moisture content threshold is 30%.

7. A system for segregated sequestering of waste material, the system comprising: a quantity of low-moisture incoming waste material comprising biomass and having a moisture content less than or equal to a moisture content threshold; a dry containment system for storing the waste material such that the moisture content of the waste material remains less than or equal to the moisture content threshold; and the system for segregated sequestering of waste material moves the quantity of the low-moisture incoming waste material to the dry containment system for storing the waste material, thereby limiting decomposition of the low-moisture incoming waste material and limiting production of carbon dioxide and/or methane gases.

8. The system for segregated sequestering of waste material of claim 7, wherein the moisture content threshold is 30%.

9. The system for segregated sequestering of waste material of claim 7, further comprising a quantity of high-moisture incoming waste material comprising biomass and having a moisture content greater than the moisture content threshold; the system for segregated sequestering of waste material having means for drying the high-moisture incoming waste material to make low-moisture waste material having a moisture content of the low-moisture waste material be less than or equal to the moisture content threshold and the system for segregated sequestering of waste material moves the low-moisture waste material to the dry containment system for storing the waste material.

10. The system for segregated sequestering of waste material of claim 7, further comprising a quantity of mixed incoming waste material comprising biomass and having high moisture content in which the moisture content is greater than the moisture content threshold and having low moisture content in which a moisture content is less than or equal to the moisture content threshold; the system for segregated sequestering of waste material having means for sorting the mixed incoming waste material to move the low moisture content in which the moisture content is less than or equal to the moisture content threshold to the dry containment system for storing the waste material.

11. The system for segregated sequestering of waste material of claim 10, further comprising means for drying content that dries the high moisture content to make low-moisture waste material having the moisture content of less than or equal to the moisture content threshold and the system for segregated sequestering of waste material moves the low-moisture waste material to the dry containment system for storing the waste material.

12. An apparatus for segregated sequestering of waste material, the waste material comprising low-moisture incoming waste material that comprises biomass material and has a moisture content less than or equal to a moisture content threshold and high-moisture incoming waste material that comprises biomass material and has the moisture content greater than the moisture content threshold, the apparatus comprising: a dry containment system for storing low-moisture waste material such that the moisture content of the low-moisture waste material remains less than or equal to the moisture content threshold thereby reducing production of carbon dioxide and methane gases; and a device moves the low-moisture incoming waste material to the dry containment system for storing the low-moisture waste material where the moisture content of the low-moisture incoming waste material is maintained at less than or equal to the moisture content threshold.

13. The apparatus for segregated sequestering of waste material of claim 12, wherein the moisture content threshold is 30%.

14. The apparatus for segregated sequestering of waste material of claim 12, further comprising means for drying the high-moisture incoming waste material to make low-moisture waste material having a moisture content of less than or equal to the moisture content threshold and after the high-moisture incoming waste material is dried to a moisture level that is less than or equal to the moisture content threshold, the device moves the low-moisture waste material to the dry containment system for storing the waste material.

15. The apparatus for segregated sequestering of waste material of claim 12, wherein the dry containment system for storing the low-moisture waste material comprises a liner that reduces moisture permeation into the low-moisture waste material.

16. The apparatus for segregated sequestering of waste material of claim 15, wherein the liner is made of high-density polyethylene.

17. The apparatus for segregated sequestering of waste material of claim 15, further comprising an outer liner, the outer liner further protecting the liner from the moisture permeation.

18. The apparatus for segregated sequestering of waste material of claim 17, wherein the outer liner is made of clay.

19. The apparatus for segregated sequestering of waste material of claim 17, wherein the outer liner is made of concrete.

20. The apparatus for segregated sequestering of waste material of claim 17, wherein the dry containment system for storing the low-moisture waste material is located in an arid area and the dry containment system for storing the low-moisture waste material is an open area.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:

(2) FIG. 1 illustrates a system and method of carbon sequestering of the prior art.

(3) FIGS. 2, 3, 3A, 4, 5, and 5A illustrate a system and method of carbon sequestering.

(4) FIG. 6, illustrates a double-lined dry containment area.

DETAILED DESCRIPTION

(5) Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures.

(6) Biomass is typically carbon that is extracted from the atmosphere by plants (even if the plant has been eaten by an animal, the carbon is still from the atmosphere). In the past, biomass was burned, composted, or placed in landfills leading to the carbon being returned to the atmosphere (e.g., as carbon dioxide and methane gases). Throughout this specification, the term waste material is used to describe biomass with or without non-biomass materials such as glass, metal, plastics, electronics, etc., without respect to the origin of the biomass material. For example, the biomass material is anticipated to be captured through recycling or it is also anticipated that the biomass material be material grown specifically for carbon sequestering. The described systems and methods are ideally suited for pure biomass, but work equally well for waste materials that are biomass plus other materials such as glass, metal, plastics, electronics, etc., though the latter are preferably exclude as there is no carbon credit given for such other materials and the costs to sequester the biomass portion of the waste material is impacted by the storage requirements of the other materials. It is far better to separate the biomass from the other materials and store the other materials in existing landfill areas.

(7) There are several methods for preventing the breakdown of carbon-based materials such as paper, cardboard, or sawdust into carbon dioxide and/or methane. Biodegradation is affected by controlling any one of the four key parameters involved in the transformation or decomposition of the carbon-based materials that produces carbon dioxide and/or methane. An environment is created that stops biological activity making it not necessary to kill the microorganisms, only to stop their biological processes. Through proper control, emission of carbon dioxide and/or methane can be prevented. The four potential parameters for control are pH, temperature, salt, and moisture. If the carbon-based materials cannot decompose due to the control of one or several such parameters, the carbon content of the carbon-based materials in its entirety is considered sequestered carbon. The disclosed segregated carbon sequestering controls one such parameter, that being moisture. By controlling moisture in the carbon-based materials, the segregated carbon sequestering prevents the breakdown of the carbon-based materials, thus eliminating associated emissions (e.g., carbon dioxide and/or methane) and enabling sequestering of the carbon.

(8) It is known that carbon-based waste material having high moisture content (e.g., moisture content greater than 30%) decays, releasing carbon dioxide and methane into the atmosphere and contributing to greenhouse gases. Many municipalities place such waste in landfills where the carbon-based waste material decomposes and emits carbon dioxide and methane into the atmosphere.

(9) Although there has been a global effort to recycle paper and paper products, such effort is slowing due to weak demand and because much of the recycled product is contaminated with materials such as plastic, paper coatings, envelope windows, food, etc., therefore much of the paper-based waste material is winding up in landfills. It should be noted that such paper-based waste and many other low-moisture waste such as sawdust, wood chips, and dry leaves, have a naturally low moisture content, usually less than 30% moisture.

(10) Referring to FIG. 1, a system and method of carbon sequestering of the prior art is shown. In this prior method of carbon sequestering, both wet incoming waste material 10 and dry incoming waste material 20 are combined into a combined wet waste material 15, are sealed in a containment 30 area of landfill. Any emitted carbon dioxide and methane produced by the wet waste material 15 are vented and processed by a scrubber/separator 32 so as not to be released into the atmosphere. In this method, there are yearly costs to operating the scrubber/separator 32 and costs of disposing or recycling the resulting biproducts.

(11) Referring to FIGS. 2, 3, 3A, 4, 5, and 5A a system and method of segregated carbon sequestering is shown. In this method of segregated carbon sequestering, the low-moisture incoming waste material 20 is stored as low-moisture waste material 27 (e.g., less than a moisture content threshold of 30%), sealed in a dry containment system 130 or dry containment area in a landfill. The high-moisture incoming waste material 10 is still stored as wet waste material 17 in the containment area 30 of the prior art as per FIG. 1, but the quantity of the wet waste material 17 is less than was stored as per the prior art. Therefore, little or no carbon dioxide and methane are released from the low-moisture waste material 27 and, therefore, the dry containment system 130 does not require venting. Note that in arid locations such as the desert southwest, it is anticipated that the dry containment system 130 be an open area as, once the low-moisture incoming waste material 20 is segregated, there is little chance that the moisture content of the low-moisture incoming waste material 20 will rise to a level in which biological activity will occur and carbon dioxide and methane will be released. In the method of segregated carbon sequestering, there are no yearly costs for operating a scrubber/separator 32 for the dry containment system 130 or costs of disposing or recycling the resulting biproducts as in the prior methods discussed with FIG. 1.

(12) The moisture content threshold of 30% is easily achieved with paper as paper products are designed to have moisture content levels of 2-10%.

(13) In FIG. 2, the method of segregated carbon sequestering incudes pre-segregating the waste material, for example, using recycling programs to collect low-moisture incoming waste material 20 (e.g., paper, cardboard, electronics) that is not contaminated with high-moisture incoming waste material 10 (e.g., food waste, diapers, wet leaves). The high-moisture incoming waste material 10 still requires a containment system 30 having a vent/scrubber 32 as in the prior art or can be sent to existing landfills, but a significant portion of the overall waste material (the low-moisture incoming waste material 20) is stored in the dry containment system 130 that reduces costs by not requiring venting and scrubbing. Note that it is fully anticipated that the low-moisture incoming waste material 20 be pre-sorted to remove and recycle reusable materials such as newspaper, metal cans, and cardboard, leaving materials such as contaminated paper (e.g., shredded paper, envelopes with plastic windows or metal fasteners, coated paper) that are stored in the dry containment system 130. It is also anticipated that non-carbon-based materials (e.g., electronics, batteries, metal) be removed and disposed through recycling, landfilling, etc.

(14) For long-term carbon sequestering, the dry containment system 130 of a landfill is anticipated to have a well-sealed, durable liner that will withstand storage demands for the desired storage time. Double geomembrane lining system polymers, such as a high-density polyethylene liner is utilized to ensure that the low-moisture waste material 27 stored within the membrane system of the dry containment system 130 remains below the moisture content threshold.

(15) As the membrane of the dry containment system must keep out moisture, it is anticipated that such liners must have a permeability of no more than 1×10.sup.−7 cm/s. The requirement for permeability delineates an impervious substance to any value below 1×10.sup.−6 cm/s. Although some moisture may leak into the system over time, the membranes currently used in landfill liners have a permeability well below 1×10.sup.−7 cm/s and, therefore, will maintain the required moisture levels for the long term. It is further anticipated that the landfill liners used in for the dry containment system 130 also have a double geomembrane lining system to further prevent water from permeating the system. In one anticipated dry containment system 130 that is double-lined, there is an outer liner is made from a sturdy material such as clay and an inner liner is made from a low-porous material such as high-density polyethylene. In such, in time, it is anticipated that water will eventually break through the outer liner, but with the smaller permeability of high-density polyethylene membranes (1×10.sup.−12 cm/s) of the inner liner, stops the water before the water reaches the low-moisture waste material 27. Selection of materials used to fabricate the dry containment system 130 is based upon the hydrodynamics of the target landfill. For example, materials used to fabricate the dry containment system 130 in a landfill with a high water table includes the above noted double-lined membrane while materials used to fabricate the dry containment system 130 in an arid area with very deep water tables include a single layer membrane or a membrane fabricated from lower-cost materials. Note in arid areas, it is anticipated that the dry containment system 130 be minimal as there is little possibility of adding moisture to the material stored therein, for example, a slab or hole dug in the ground.

(16) In FIG. 3, another embodiment of the segregated carbon sequestering incudes pre-segregating the waste material, for example, using recycling programs to collect low-moisture incoming waste material 20 (e.g., paper, cardboard, electronics) that is not contaminated with high-moisture waste material 10 (e.g., food waste, diapers, wet leaves). A sorter 140 separates the high-moisture incoming waste material 10 based upon moisture content and the portion of the high-moisture incoming waste material 10 that has a high moisture content still requires a containment system 30 having a vent/scrubber 32 for storing the wet waste material 17 (or is moved to contemporary landfills 37 as in FIG. 3A) as in the prior art. but a more significant portion of the overall waste material (the low-moisture waste material 27) is stored in the dry containment system 130 that reduces costs by not requiring venting and scrubbing. The sorter 140 separates materials moving materials with high moisture content (e.g., wet diapers, food, wet leaves) to containment system 30 having a vent/scrubber 32 or to contemporary landfills 37 as in the prior art. In some embodiments, as shown in FIG. 3A, the remaining waste material that has little or no moisture content is moved to the dry containment system 130. Although it is anticipated that some low-moisture non-carbon materials be moved to the dry containment system 130, it is preferred that only low-moisture dry carbon-based materials be stored in the dry containment system 130.

(17) Note again that it is fully anticipated that the low-moisture incoming waste material 20 be pre-sorted to remove and recycle reusable materials such as newspaper, metal cans, and cardboard, leaving materials such as contaminated paper (e.g., shredded paper, envelopes with plastic windows or metal fasteners, coated paper) that are stored in the dry containment system 130.

(18) In FIG. 4, another embodiment of the segregated carbon sequestering incudes pre-segregating the waste material, for example, using recycling programs to collect low-moisture incoming waste material 20 (e.g., paper, cardboard, electronics) that is not contaminated with high-moisture incoming waste material 10 (e.g., food waste, diapers, wet leaves). In this embodiment, the high-moisture incoming waste material 10 is dried by a drying system 150 to reduce the moisture content to a point below which the resulting waste material will not produce carbon monoxide and/or methane (e.g., to a moisture content below approximately 30%). In this embodiment, all of the overall waste material (the low-moisture incoming waste material 20 and the dried high-moisture incoming waste material 10) is stored in the dry containment system 130, reducing costs by not requiring venting and scrubbing. Again, it is anticipated that the high-moisture incoming waste material 10 will included some amount of non-carbon-based material, but it is preferred to limit the amount of non-carbon-based material that is moved to the dry containment system 130 as the non-carbon-based material is better stored in contemporary landfills 37 at a lower cost.

(19) Therefore, the yearly costs of operating the containment system 30 with venting 32 are eliminated, but initial costs such as energy costs for the drying system 150 are incurred.

(20) In FIG. 5, another embodiment of the segregated carbon sequestering incudes pre-segregating the waste material, for example, using recycling programs to collect low-moisture incoming waste material 20 (e.g., paper, cardboard, electronics) that is not contaminated with high-moisture incoming waste material 10 (e.g., food waste, diapers, wet leaves). In this embodiment, the sorter 140 removes materials that have little or no moisture content from the high-moisture incoming waste material 10 such as plastics, plastic foam (e.g., egg cartons), metals, glass (e.g., light bulbs) which go directly to the dry containment system 130. The remaining high-moisture incoming waste material 10 from the sorter 140 is then dried by the drying system 150 to reduce the moisture content to a point below that in which the resulting waste material will produce carbon monoxide and/or methane (e.g., to a moisture content below 30%). In this embodiment, all of the overall waste material (the low-moisture waste material 20 and the sorted/dried high-moisture waste material 10) is stored in the dry containment system 130, reducing costs by not requiring venting and scrubbing. Therefore, the yearly costs of operating the containment system 30 with venting 32 are eliminated, but initial costs such as energy costs for the sorting system 140 and drying system 150 are incurred, but it is anticipated that the cost of sorting is lower than the energy costs associated with drying, therefore it is economical to sort first before drying.

(21) It should be noted that it is anticipated that the drying system 150 be any system that will dry the high-moisture incoming waste material 10 to the desired moisture content, including, but not limited to, air-drying (e.g., on racks) and thermal drying (e.g., using heated tumblers).

(22) In some embodiments, as shown in FIG. 5A, the sorting system 140 removes at least some non-biomass waste material (e.g., rock, glass, metal, electronics) and moves this non-biomass waste material to the contemporary landfills 37 or other lower-cost storage area. The remaining waste material that is predominately biomass is then dried by the drier 150 to reduce the moisture content to a moisture content that is lower than needed to prevent decomposition (e.g., lower than a moisture threshold of approximately 30%) and then moved to the dry containment system 130. Although it is anticipated that some low-moisture non-carbon materials be moved to the dry containment system 130, it is preferred that only low-moisture dry carbon-based materials (e.g., biomass) be stored in the dry containment system 130.

(23) Referring to FIG. 6, a double-lined dry containment system 130A is shown. In this, there is an outer liner 131 made of a material such as clay or concrete and an inner liner 133 made of a low-porous material such as high-density polyethylene. In such, in time, it is anticipated that water will eventually break through the outer liner 131, but with the smaller permeability of the inner liner 133 (e.g., made of high-density polyethylene membranes (1×10.sup.−12 cm/s)), the water is be stopped before reaching the low-moisture waste material 20. Selection of materials used to fabricate the inner liner 133 and the outer liner 131 are based upon the hydrodynamics of the target landfill.

(24) Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.

(25) It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.