METHODS AND SYSTEMS FOR BIOMASS-DERIVED CO2 SEQUESTRATION IN CONCRETES AND AGGREGATES

Abstract

Provided herein are integrated biomass combustion-carbonation gas conditioning systems to directly sequester carbon dioxide from biomass-derived CO.sub.2-containing flue gas. The CO.sub.2 is sequestered by mineral carbonation in concrete materials within a carbonation reactor. The mineral carbonation processes sequester CO.sub.2 in concrete materials, aqueous slurries, or aggregates without any additional carbon enrichment process. Contacting a CO.sub.2-containing gas stream from a biomass combustion apparatus with concrete, aggregate, or alkaline solutions, causes a carbonation reaction in which carbonation products such as calcium carbonate (CaCO.sub.3) and alumina silica gel are formed. The carbonation reactions set forth herein are useful for strengthening concrete and concrete components. Certain processes herein condition the biomass-derived flue gas. The conditioning includes condensing the gas to remove acidic gas, and to remove particulates and water. The conditioning includes adjusting the temperature, relative humidity, and gas flow rate of the biomass-derived flue gas without any carbon capture step before entering the carbonation reactor. The permanent storage of CO.sub.2 in concrete materials reduces carbon emissions from biomass combustion systems. The process does so, in certain embodiments, at low temperatures, ambient pressure, and even under dilute CO.sub.2 concentrations in CO.sub.2-containing flue gas streams. For example, the CO.sub.2 concentration in a CO.sub.2-containing flue gas stream from a biomass combustion system may be lower than 20 volume percent (vol %) and be used to produce low-carbon concrete materials.

Claims

1. A process for sequestering carbon dioxide from a biomass combustion apparatus, comprising providing a CO.sub.2-containing flue gas from a biomass combustion apparatus having a biomass discharge outlet; conditioning the CO.sub.2-containing flue gas to provide a conditioned gas; wherein the conditioning comprises: removing a member selected from the group consisting of particulate matter, acidic gas, alkali chlorides, alkali sulfates, and combinations thereof; and adjusting the temperature, relative humidity, flow rate, or a combination thereof, of the CO.sub.2-containing flue gas; wherein the conditioned gas has a different temperature, relative humidity, flow rate, or a combination thereof, than the CO.sub.2-containing flue gas at the biomass discharge outlet; and wherein the conditioned gas has the same concentration of CO.sub.2 as the CO.sub.2-containing flue gas at the biomass discharge outlet; contacting, in a carbonation chamber, the conditioned gas with a component selected from the group consisting of a green body, concrete, an aqueous solution of alkaline solids, an aqueous solution of aggregates, or a combination thereof; and precipitating calcium carbonate at ambient pressure and temperatures ranging from, and including, 20° C. to 100° C.

2. The process of claim 1, wherein the conditioned gas is directly transferred to the carbonation chamber without using an additional CO.sub.2 capture or enrichment process step.

3. The process of claim 1 , wherein the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is less than 20% by volume.

4. (canceled)

5. (canceled)

6. The process of claim 3 FM wherein the average CO.sub.2 conversion efficiency via mineral carbonation from biomass CO.sub.2 emission ranges from about 30% to 95%.

7. (canceled)

8. The process of claim 1, wherein the carbonation chamber is a flow-through reactor, an aqueous reactor, a slurry reactor, or a stirring reactor.

9. (canceled)

10. The process of claim 1, wherein the carbonation chamber is at ambient pressure and a temperature in a range from about 20° C. to about 100° C.

11.-13. (canceled)

14. The process of claim 1, wherein the concrete comprises hydrated lime, cement kiln dust, lime kiln dust, carbide lime, lime residues, portland cement, coal combustion residues, recycled concrete aggregates, natural pozzolans, other industrial solid wastes, a combination thereof, the carbonation products thereof, or the hydration products thereof.

15. The process of claim 1, comprising contacting, in the carbonation chamber, the conditioned gas with an aqueous solution of alkaline solids, wherein the aqueous solution of alkaline solids comprises coal combustion residues, recycled concrete aggregates, slag, portland cement, hydrated lime, lime kiln dust, cement kiln dust, other industrial alkaline solid wastes, or a combination thereof.

16. The process of claim 15, wherein the aggregates are selected from coal combustion residues, recycled concrete aggregates, slag, lime, lime kiln dust, natural alkaline rocks, other industrial alkaline solid wastes, or combinations thereof.

17. (canceled)

18. The process of claim 1, wherein the gas processing apparatus comprises: at least one gas cleaning system, at least one condenser, at least one heat exchanger, at least one blower; and at least one air cooler or water chiller.

19. (canceled)

20. The process of claim 1, wherein heat from the biomass combustion apparatus is conducted to the CO.sub.2-containing flue gas by hot air, hot water, steam, heat recovery from flue gas cooling, or a combination thereof.

21.-13. (canceled)

24. The process of claim 1, further comprising: providing a biomass feedstock in the biomass combustion apparatus; and drying the feedstock if the feedstock has a moisture content greater than, or equal to, 30% by weight (w/w) to reduce carbon monoxide (CO) and volatile organic compounds (VOC), or a combination.

25-18. (canceled)

29. The process of claim 1, comprising providing a conditioned gas which increases the rate of carbonation in the carbonation chamber.

30. The process of claim 1, wherein the conditioned gas has a temperature, relative humidity, CO.sub.2 amount, gas stream flow rate, or a combination thereof to provide a carbonation rate constant of the precursor that is at or above 0.005.

31. The process of claim 1, comprising recirculating the conditioned gas out of and back into the carbonation chamber.

32.-34. (canceled)

35. The process of claim 1, comprising flowing the CO.sub.2-containing flue gas through a gas cleaning systems such as cyclone, baghouse filter, wet scrubber, or electrostatic precipitator to reduce particulate matter and acidic gases present in the CO.sub.2-containing flue gas.

36. The process of claim 1, wherein the carbonation products are mainly calcium carbonate and alumina-silica gel, or a combination thereof.

37.-38. (canceled)

39. The process of claim 1, wherein the process occurs in a flow-through reactor.

40. (canceled)

41. (canceled)

42. The process of claim 1, wherein the process occurs in a stirring reactor.

43.-59. (canceled)

60. An apparatus comprising: a biomass combustion apparatus coupled to a gas processing apparatus; wherein the gas processing apparatus is coupled to at least one or more carbonation chambers; where the gas process apparatus is configured to condition CO.sub.2-containing flue gas from the biomass combustion apparatus to produce a conditioned gas; wherein the conditioned gas has a different temperature, relative humidity, flow rate, or a combination thereof, than the CO.sub.2-containing flue gas; and wherein the conditioned gas has the same concentration of CO.sub.2 as the CO.sub.2-containing flue gas without any carbon capture step.

61.-67. (canceled)

Description

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0013] FIG. 1 shows a diagram illustrating the negative carbon emission pathway of biomass energy with carbon sequestration.

[0014] FIG. 2 shows a diagram illustrating the integration of biomass combustion equipment to sequester CO.sub.2 in concrete, aqueous solution, and/or aggregate materials.

[0015] FIG. 3 shows a process flow diagram for using biomass-derived CO.sub.2 sequestration in concrete, aqueous solution, and/or aggregate production.

[0016] FIG. 4 shows a biomass combustion apparatus used at a concrete block manufacturing facility.

[0017] FIG. 5 shows a plot of CO.sub.2 concentration (vol %) of flue gas at biomass combustion discharge outlet point over 12 hours.

[0018] FIG. 6 shows a plot of temperature (° F.) of the biomass flue gas at the biomass combustion outlet (TT01), after cooling at condenser outlet (TT07), and after heating at heat exchanger outlet (TT03) over 12 hours.

[0019] FIG. 7 shows a plot of CO.sub.2 concentration (vol %) at a carbonation reactor chamber inlet and outlet points over 12 hours of carbonation curing of concrete blocks. AE01 (top plot) and AE04 (bottom plot) are CO.sub.2 vol % measurements at the carbonation reactor chamber inlet and outlet points respectively. The difference between inlet and outlet CO.sub.2% is related to CO.sub.2 absorption via mineral carbonation in the concrete blocks in the carbonation reactor.

DETAILED DESCRIPTION

Definitions

[0020] As used herein, the singular terms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to an object can include multiple objects unless the context clearly dictates otherwise.

[0021] As used herein, the term “set” refers to a collection of one or more objects. Thus, for example, a set of objects can include a single object or multiple objects.

[0022] As used herein, the terms “substantially” and “about” are used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs to a close approximation. For example, when used in conjunction with a numerical value, the terms can encompass a range of variation of less than or equal to ±10% of that numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.

[0023] As used herein, the term “size” refers to a characteristic dimension of an object. Thus, for example, a size of an object that is circular can refer to a diameter of the object. In the case of an object that is non-circular, a size of the non-circular object can refer to a diameter of a corresponding circular object, where the corresponding circular object exhibits or has a particular set of derivable or measurable characteristics that are substantially the same as those of the non-circular object. Alternatively, or in conjunction, a size of a non-circular object can refer to an average of various orthogonal dimensions of the object. Thus, for example, a size of an object that is an ellipse can refer to an average of a major axis and a minor axis of the object. When referring to a set of objects as having a particular size, it is contemplated that the objects can have a distribution of sizes around the particular size. Thus, as used herein, a size of a set of objects can refer to a typical size of a distribution of sizes, such as an average size, a median size, or a peak size.

[0024] Herein, the phrase “the conditioned gas has substantially the same concentration of CO.sub.2 as the CO.sub.2-containing flue gas without any carbon capture step,” means that the conditioned gas and the CO.sub.2-containing flue gas have CO.sub.2 concentrations (by volume) that are within 1% of each other.

[0025] Herein, the phrase “without any carbon capture step,” means that the concentration of the CO.sub.2 in the CO.sub.2-containing flue gas at the biomass combustion apparatus discharge outlet is not enriched with, or increased by, for example, a CO.sub.2 capture processes.

[0026] Additionally, amounts, ratios, and other numerical values are sometimes presented herein in a range format. It is to be understood that such range format is used for convenience and brevity and should be understood flexibly to include numerical values explicitly specified as limits of a range, but also to include all individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly specified. For example, a ratio in the range of about 1 to about 200 should be understood to include the explicitly recited limits of about 1 and about 200, but also to include individual ratios such as about 2, about 3, and about 4, and sub-ranges such as about 10 to about 50, about 20 to about 100, and so forth.

[0027] As used herein, “biomass feedstock,” includes any source of biologically-produced mass which may be burned to produce energy while sequestering the CO.sub.2 to make products. Biomass includes, but is not limited to, wood chips, wood pellets, and sawdust.

[0028] As used herein, recycled concrete aggregate is a form of crushed concrete formulated into a paste. “Recycled concrete aggregates,” may also refer to previously formed concrete milled/ground up.

[0029] As used herein, “carbonated materials” refers to materials made by contacting CO.sub.2 to an alkaline-rich mineral material. Carbonate materials include, but are not limited to, calcium carbonate, calcite, vaterite, aragonite, or a combination thereof. Carbonated materials may include oxides, hydroxides, carbonates, silicates, sulfites, sulfates, chlorides, nitrates, or nitrites of calcium and/or magnesium and/or other uni-/multi-valent elements, or any combination thereof.

[0030] As used herein, the term “a carbonated concrete composite,” refers to a carbonated concrete object (e.g., a building material) made from early-age (e.g., fresh) concrete that is then contacted with a CO.sub.2-containing curing gas having a suitable CO.sub.2 concentration.

[0031] As used herein, the term “other industrial alkaline solid wastes,” or “other industrial solid wastes,” refers to materials such as, but not limited to, alkaline-rich mineral materials.

[0032] Herein, a “residue” is a material that has been used, for example, in concrete production; or in a flue gas treatment, for example, as a sorbent or scrubbing material that are used for flue gas treatment or byproducts that are generated during industrial processes such as cement and lime manufacturing. A residue may include hydrated lime, lime kiln dust, cement kiln dust, fly ash, limestone, or combinations thereof. A residue may be referred to in the art as a mineral sorbent.

[0033] As used herein, “alkaline-rich mineral materials” refers to virgin, byproduct, or residue materials which include Ca and/or Mg. Alkaline-rich mineral materials include, but are not limited to, Ca(OH).sub.2, lime kiln dust, lime, hydrated lime, cement kiln dust, calcium-rich coal combustion residues, slag, off-spec fly ashes, biomass ashes, fluidized bed combustion ashes, circulating fluidized bed ashes, off-spec limes, mineral sorbent/scrubbing residues comprising anhydrous CaO and/or Ca(OH).sub.2, and combinations thereof. The alkaline-rich mineral materials may further comprise at least one of oxides, hydroxides, carbonates, silicates, sulfites, sulfates, chlorides, nitrates, or nitrites of calcium and/or magnesium, or any combination thereof.

[0034] As used herein, the “reaction medium” is the environment in the carbonation chamber.

[0035] As used herein, the “mineral carbonation reactor” is a reactor used to produce calcium carbonate by exposing, in a confined space, alkaline-rich mineral materials, aggregates, green body, concrete, or any combination thereof to a CO.sub.2-containing gas stream.

[0036] As used herein, the term “active carbonation,” refers to a process which results in a carbonation reaction rate that is above a natural value. For example, a carbonation rate at or above 0.005 per hour is a non-limiting example of active carbonation.

[0037] As used herein, the term “flow-through chamber,” refers to a chamber through which gas may be flowed continuously and at ambient pressure.

[0038] As used herein, the term “ambient pressure,” refers to atmospheric pressure on planet Earth.

[0039] As used herein, the term “a carbonated concrete composite,” refers to a carbonated concrete object (e.g., a building material) made from early-age (e.g., fresh) concrete that is then contacted with a CO.sub.2-containing curing gas having a suitable CO.sub.2 concentration.

[0040] As used herein, the term “material performance of a carbonated concrete composite” is defined as porosity, compressibility, and/or other mechanical or strength measurement (e.g., Young's modulus, yield strength, ultimate strength, fracture point, etc.).

[0041] As used herein, the term “negatively affecting the material performance,” refers to a material performance that is reduced in magnitude by a factor of 10 or more.

[0042] As used herein, the term “uniform material performance of a carbonated concrete component,” refers to substantially uniform material properties throughout the concrete component. That is, there are no significant gradients or variations in material performance from one area of the concrete composite to another area of the concrete composite.

[0043] As used herein, the term “ material performance gradient,” refers to a spatial difference in porosity and/or compressibility in the carbonated concrete composite. In various embodiments, for uniform material performance, the porosity, measured as a volume percent, and/or the compressibility does not vary by more than ±25% over a concrete volume unit of 1 m.sup.3. In various embodiments, for uniform material performance, the porosity and/or compressibility does not vary by more than ±20% over a concrete volume unit of 1 m.sup.3. In various embodiments, for uniform material performance, the porosity and/or compressibility does not vary by more than ±15% over a concrete volume unit of 1 m.sup.3. In various embodiments, for uniform material performance, the porosity and/or compressibility does not vary by more than ±10% over a concrete volume unit of 1 m.sup.3. In various embodiments, for uniform material performance, the porosity and/or compressibility does not vary by more than ±10% over a concrete volume unit of 10 cm.sup.3. In various embodiments, for uniform material performance, the porosity and/or compressibility does not vary by more than ±5% over a concrete volume unit of 10 cm.sup.3. In various embodiments, for uniform material performance, the porosity and/or compressibility does not vary by more than ±1% over a concrete volume unit of 10 cm.sup.3. For example, the compressibility may be measured according to ASTM C140 under uniaxial monotonic displacement-controlled loading using a hydraulic jack with a capacity of 800 kN. In this example, the carbonated concrete composite does not have a material performance gradient if the compressibility does not vary by more than ±10%, preferably ±5% over a concrete volume unit of 10 cm.sup.3.

[0044] As used herein, the term “gas conditioning apparatus,” refers to a system which is configured to receive a CO.sub.2-containing flue gas stream and adjust the temperature, relative humidity, flow rate, or a combination thereof, of the CO.sub.2-containing flue gas stream before flowing the CO.sub.2-containing flue gas stream out of the gas conditioning apparatus. A gas conditioning apparatus may also remove particulate matter, acidic gas alkali chlorides, alkali sulfates, and combinations thereof.

[0045] As used herein, the term “acidic gas” refers to gaseous sulfate or sulfate-including compounds, gaseous chlorine or chlorine-including compounds, and/or gaseous NO.sub.x (e.g., NO.sub.2, NO.sub.3, combinations thereof).

[0046] As used herein, the term “coupled to,” refers to an electrical, digital, mechanical, wireless, Bluetooth, connection between one or more apparatus. Herein, “coupled to” and “integrated into” mean, unless specified otherwise to the contrary, that the objects coupled or integrated are mechanically connected to each other.

[0047] As used herein, the term “conditioned CO.sub.2-containing flue gas stream,” refers to a CO.sub.2-containing flue gas stream wherein the incoming flue gas is first condensed to capture acidic gas and alkaline metals to minimize corrosion problems followed by adjusting temperature, relative humidity, flow rate, or a combination thereof, before introducing the gas into a carbonation reactor.

[0048] As used herein, the term “green body,” refers to a concrete precursor.

[0049] As used herein, the term “rate of carbonation,” refers to the rate which CO.sub.2 is consumed. To quantify the carbonation kinetics, the time-CO.sub.2 uptake profiles are fitted to an equation of the form

C(t)=C(t.sub.u)(1−exp[(−k.sub.carbt)/C(t.sub.u)])   (6)

where k.sub.carb is the apparent carbonation rate constant and C(t.sub.u) is the ultimate CO.sub.2 uptake at the end of carbonation curing duration.

[0050] For example, carbonation at or above 0.005 per hour means that k.sub.carb is a value 0.005 or greater. This would include but is not limited to, k.sub.carb of 0.05, or 0.5, or 1, or 2.

[0051] As used herein, the term “CO.sub.2 conversion efficiency %” is defined as the average CO.sub.2 uptake divided by the CO.sub.2 input over the period of carbonation curing. The extent of carbonation conversion and carbonation rate refers to the weight of calcium carbonate formed from the starting material, e.g., OPC or LKD.

[0052] As used herein, the phrase “mainly calcium carbonates and alumina-silica gel,” refers to a product mixture that is more than 50% by weight calcium carbonate. In some embodiments, the mixture is more than 90% by weight calcium carbonate. In some embodiments, including any of the foregoing, when two starting materials are used, such as LKD and fly ash, in which one starting material includes Al phases, Si phases, or both, then both calcium carbonate and alumina-silica carbonates may form during carbonation curing. In some other embodiments, when one starting material, such as portlandite, is used and which only includes Ca(OH).sub.2, then calcium carbonate may form but alumina-silica carbonates will not form during carbonation curing.

Systems

[0053] FIG. 1 shows a process, 100. The top process includes step 101 of biomass production. This is followed by step 102 which is biomass transportation. Next, step 103 includes biomass combustion. The last step is step 104, which includes carbon sequestration.

[0054] The bottom process in FIG. 1 includes step 105 of capturing atmospheric CO.sub.2 in biomass. This is followed by step 106 which is providing biomass. Next, step 107 includes biomass combustion. After combustion, is step 108, which includes the conversion of biomass to energy, and step 109, which includes CO.sub.2 release. After step 109, there is step 110 of a carbon sequestration process from biomass-derived flue gas.

[0055] FIG. 2 shows an example process for integrating biomass-derived CO.sub.2-containing flue gas streams into a carbonation sequestration system, 200. Panel 201 shows a list of possible raw materials. These raw materials, 209, 210, 211, 212, and 213, include, but are not limited to, hydrated lime, fly ash, cement, aggregates, water, and combinations thereof. The raw materials, 209-213, are processed using concrete production equipment, shown as 214. This processing of raw materials, 209-213, produces fresh concrete or fresh alkaline-rich aqueous slurry, 202, or both, in some instances. The fresh concrete or fresh alkaline-rich aqueous slurry is placed in a curing chamber, 215. Also shown is the production of a CO.sub.2-containing flue gas, 204. The CO.sub.2-containing flue gas, 204, is produced from biomass combustion equipment, 216. The biomass combustion equipment, 216, is further detailed herein and may include any system for burning biomass in a way that captures the combustion product gases without directly releasing these gases into the atmosphere. The biomass combustion equipment, 216, produces the CO.sub.2-containing flue gas, 204. To condition such as removing acidic gas and adjusting temperature, relative humidity, and gas flow rate of CO.sub.2 containing flue gas, 204, is processed using gas processing equipment, 217. The processing of the CO.sub.2-containing flue gas, 204, in the gas processing equipment, 217, results in a conditioned gas stream, shown as 205. The conditioned gas stream, 205, contacts the fresh concrete, alkaline-rich aqueous slurry or aggregates, 202, in the curing chamber, 215. This results in carbonation reactions in the concrete, slurry, or aggregate. The carbonation reactions reduce the amount of CO.sub.2 in the conditioned gas stream, 205, which results in CO.sub.2-depleted gas, 206. Also produced is recycled water, 207. The CO.sub.2-depleted gas, 206, and recycled water, 207, is transported through a gas recycling system, 218. Some of the gas in the gas recycling system, 218, is recycled back into the system with the CO.sub.2-containing flue gas, 204. Some of the gas in the gas recycling system, 218, is exhausted into the atmosphere as shown in 208.

[0056] FIG. 3 shows an example process flow diagram for Biomass Integration. FIG. 3 shows a [1] Biomass combustion system coupled to a [2] Gas processing system coupled to [3] Carbonation Chamber(s). The Biomass combustion system includes moist wood chips, 301.

[0057] These moist wood chips, 301, are dried in the wood chip dryer, 302, to produce dry wood chips, 303. Hot air, 304, may circulate through the wood chip dryer, 302. The dry wood chips, 303, are loaded into a biomass combustion apparatus, 305, which produces hot air, 304, ash, 306, and flue gas, 307. FIG. 3 also shows a [2] gas processing apparatus, which includes a system that include a gas scrubber, chiller, condenser, heat exchangers, blowers to condition temperature, relative humidity, and flow rate of the biomass-derived CO.sub.2-containing flue gas. FIG. 3 also shows [3] Carbonation Chambers. FIG. 3 shows curing chamber, 310, with exhaust outlet, 311. Other carbonation chambers are contemplated but not shown.

Embodiments

[0058] In some embodiments, set forth herein is a process for sequestering carbon dioxide, comprising providing a CO.sub.2-containing flue gas from a biomass combustion apparatus; conditioning the CO.sub.2-containing flue gas to provide a conditioned gas; wherein the conditioning comprises removing a compound selected from the group consisting of particulate matter, acidic gas, alkali chlorides, alkali sulfates, and combinations thereof; and wherein the conditioned gas has a different temperature, relative humidity, flow rate, or a combination thereof, than the CO.sub.2-containing flue gas; and wherein the conditioned gas has substantially the same concentration of CO.sub.2 as the CO.sub.2-containing flue gas; contacting, in a carbonation chamber, the conditioned gas with a member selected from the group consisting of a green body, concrete, an aqueous solution of alkaline solids, aggregates, or a combination thereof; and precipitating calcium carbonate.

[0059] In some embodiments, set forth herein is a process for sequestering carbon dioxide from a biomass combustion apparatus, comprising providing a CO.sub.2-containing flue gas from a biomass combustion apparatus having a biomass discharge outlet; conditioning the CO.sub.2-containing flue gas to provide a conditioned gas; wherein the conditioning comprises: removing a member selected from the group consisting of particulate matter, acidic gas, alkali chlorides, alkali sulfates, and combinations thereof; and adjusting the temperature, relative humidity, flow rate, or a combination thereof, of the CO.sub.2-containing flue gas; wherein the conditioned gas has a different temperature, relative humidity, flow rate, or a combination thereof, than the CO.sub.2-containing flue gas at the biomass discharge outlet; and wherein the conditioned gas has the same concentration of CO.sub.2 as the CO.sub.2-containing flue gas at the biomass discharge outlet;

[0060] contacting, in a carbonation chamber, the conditioned gas with a component selected from the group consisting of a green body, concrete, an aqueous solution of alkaline solids, an aqueous solution of aggregates, or a combination thereof; and precipitating calcium carbonate at ambient pressure and temperatures ranging from, and including, 20° C. to 100° C.

[0061] In some embodiments, including any of the foregoing, the process includes contacting, in a carbonation chamber, the conditioned gas with concrete.

[0062] In some embodiments, including any of the foregoing, the carbonation chamber is flow-through reactor.

[0063] In some embodiments, including any of the foregoing, the carbonation chamber is at ambient pressure.

[0064] In some embodiments, including any of the foregoing, the carbonation chamber is at a temperature from about 20° C. to about 100° C.

[0065] In some embodiments, including any of the foregoing, the carbonation chamber is at a temperature from about 20° C. to about 80° C.

[0066] In certain embodiments, the carbonation chamber is at 20° C. In certain embodiments, the carbonation chamber is at 25° C. In certain embodiments, the carbonation chamber is at 30° C. In certain embodiments, the carbonation chamber is at 35° C. In certain embodiments, the carbonation chamber is at 40° C. In certain embodiments, the carbonation chamber is at 45° C. In certain embodiments, the carbonation chamber is at 50° C. In certain embodiments, the carbonation chamber is at 55° C. In certain embodiments, the carbonation chamber is at 60° C. In certain embodiments, the carbonation chamber is at 65° C. In certain embodiments, the carbonation chamber is at 70° C. In certain embodiments, the carbonation chamber is at 75° C. In certain embodiments, the carbonation chamber is at 80° C.

[0067] In some embodiments, including any of the foregoing, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is about 5 to 20% by volume.

[0068] In some embodiments, including any of the foregoing, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is about 5 to 18% by volume.

[0069] In some embodiments, including any of the foregoing, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is about 5to 15% by volume.

[0070] In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 5% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 6% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 7% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 8% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 9% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 10% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 11% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 12% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 13% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 14% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 15% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 16% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 17% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 18% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 19% by volume. In certain embodiments, the concentration of CO.sub.2 in the CO.sub.2-containing flue gas is 20% by volume.

[0071] In some embodiments, including any of the foregoing, the concentration of CO in the CO.sub.2-containing flue gas is about 1 to 1000 ppm.

[0072] In some embodiments, including any of the foregoing, the process includes contacting, in a carbonation chamber, the conditioned gas with an aqueous solution of alkaline solids.

[0073] In some embodiments, including any of the foregoing, the process includes contacting, in a carbonation chamber, the conditioned gas with an aqueous solution of aggregates.

[0074] In some embodiments, including any of the foregoing, the concrete comprises hydrated lime, portland cement, coal combustion residues, recycled concrete aggregates, other industrial solid wastes, or a combination thereof.

[0075] In some embodiments, including any of the foregoing, the aqueous solution of alkaline solids comprises coal combustion residues, recycled concrete aggregates, slag, portland cement, hydrated lime, lime kiln dust, cement kiln dust, other industrial alkaline solid wastes, or a combination thereof.

[0076] In some embodiments, including any of the foregoing, the aggregates are selected from coal combustion residues, recycled concrete aggregates, slag, lime, lime kiln dust, natural alkaline rocks, other industrial alkaline solid wastes, or combinations thereof.

[0077] In some embodiments, including any of the foregoing, the CO.sub.2-containing flue gas flows through exhaust discharge points of the biomass combustion apparatus.

[0078] In some embodiments, including any of the foregoing, the conditioning comprises passing the CO.sub.2-containing flue gas through a gas conditioning apparatus to adjust at least one parameter selected from temperature, relative humidity, and gas flow rate.

[0079] In some embodiments, including any of the foregoing, the gas processing apparatus comprises: [0080] at least one gas cleaning system [0081] at least one condenser, [0082] at least one heat exchanger, [0083] at least one blower; and [0084] at least one air cooler or chiller. In some embodiments, the gas cleaning system is a gas scrubber.

[0085] In some embodiments, including any of the foregoing, the particulate matter comprises ash.

[0086] In some embodiments, including any of the foregoing, the acidic gas comprises sulfur oxide.

[0087] In some embodiments, including any of the foregoing, the acidic gas comprises SO.sub.x wherein x is 1 from 4.

[0088] In some embodiments, including any of the foregoing, the alkali chlorides are selected from KCl, NaCl, or a combination of KCl and NaCl.

[0089] In some embodiments, including any of the foregoing, the alkali sulfates are selected from KlSO.sub.4.

[0090] In some embodiments, including any of the foregoing, the process further includes: providing a biomass feedstock in the biomass combustion apparatus; and drying the feedstock if the feedstock has a moisture content greater than, or equal to, 30% by weight (w/w).

[0091] In some embodiments, including any of the foregoing, the process further includes: providing a biomass feedstock in the biomass combustion apparatus; and reducing acidic gas, alkaline content, particulate content, carbon monoxide (CO), volatile organic compounds (VOC), or a combination thereof, in the CO.sub.2-containing flue gas by drying the feedstock.

[0092] In some embodiments, including any of the foregoing, the process does not further include a CO.sub.2 enrichment step.

[0093] In some embodiments, including any of the foregoing, the process does not further include any CO.sub.2 purification steps other than removing a compound selected from the group consisting of particulate matter, acidic gas, alkali chlorides, alkali sulfates, and combinations thereof.

[0094] In some embodiments, including any of the foregoing, the CO.sub.2-containing flue gas from biomass combustion apparatus has a temperature ranging from about 75° C. to about 200° C.

[0095] In some embodiments, including any of the foregoing, the CO.sub.2-containing flue gas from biomass combustion apparatus has a temperature ranging from about 20° C. to about 100° C.

[0096] In some embodiments, including any of the foregoing, the CO.sub.2-containing flue gas from biomass combustion apparatus has a temperature ranging from about 20° C. to about 80° C.

[0097] In some embodiments, including any of the foregoing, the CO.sub.2-containing flue gas from biomass combustion apparatus has a temperature ranging from about 50° C. to about 100° C.

[0098] In some embodiments, including any of the foregoing, the process includes cooling the CO.sub.2-containing flue gas to condense acidic, alkaline, and particulate compounds followed by adjusting temperature, relative humidity, and flow rate before entering the carbonation chamber consisting of a green body, concrete, an aqueous solution of alkaline solids, an aqueous solution of aggregates, or a combination thereof.

[0099] In some embodiments, including any of the foregoing, the process includes providing a conditioned gas which increases the rate of carbonation in the carbonation chamber.

[0100] In some embodiments, including any of the foregoing, the conditioned gas has a temperature, relative humidity, CO.sub.2 amount, gas stream flow rate, or a combination thereof to provide a carbonation rate constant of the precursor that is at or above 0.005.

[0101] In some embodiments, including any of the foregoing, the process includes recirculating the conditioned gas out of and back into the carbonation chamber.

[0102] In some embodiments, including any of the foregoing, the process includes removing water from the carbonation chamber.

[0103] In some embodiments, including any of the foregoing, the CO.sub.2-containing flue gas flows, through a condenser, air cooler, heat exchanger, a heater, a blower, a chiller or a combination thereof in the gas processing apparatus.

[0104] In some embodiments, including any of the foregoing, the conditioned gas increases the rate of carbonation in the precursor.

[0105] In some embodiments, including any of the foregoing, the conditioned gas has a temperature ranging from about 20° C. to about 90° C.

[0106] In some embodiments, including any of the foregoing, the conditioned gas has a relative humidity ranging from about 10% to about 90%. In certain embodiments, the conditioned gas has a relative humidity of 10%. In certain embodiments, the conditioned gas has a relative humidity of 20%. In certain embodiments, the conditioned gas has a relative humidity of 30%. In certain embodiments, the conditioned gas has a relative humidity of 40%. In certain embodiments, the conditioned gas has a relative humidity of 50%. In certain embodiments, the conditioned gas has a relative humidity of 60%. In certain embodiments, the conditioned gas has a relative humidity of 70%. In certain embodiments, the conditioned gas has a relative humidity of 80%.

[0107] In some embodiments, including any of the foregoing, the conditioned gas has a flow rate of at least 100 standard cubic feet per minute (scfm). In certain embodiments, the conditioned gas has a flow rate of less than 25,000 (scfm).

[0108] In some embodiments, including any of the foregoing, the process includes atomizing water into the conditioned gas to humidify the gas and increase relative humidity.

[0109] In some embodiments, including any of the foregoing, the process includes flowing the CO.sub.2-containing flue gas through a gas cleaning system such as cyclone, baghouse filter, wet scrubber, or electrostatic precipitator to reduce biomass ash and alkali chlorides present in exhaust gas before entering the gas processing system.

[0110] In some embodiments, including any of the foregoing, the calcium carbonate is vaterite, aragonite, calcite, or a combination thereof.

[0111] In some embodiments, including any of the foregoing, the process is a semi-dry process.

[0112] In some embodiments, including any of the foregoing, the process occurs in a flow-through reactor.

[0113] In some embodiments, including any of the foregoing, the process is an aqueous process.

[0114] In some embodiments, including any of the foregoing, the process is a slurry process.

[0115] In some embodiments, including any of the foregoing, the process occurs in a stirring reactor.

[0116] In some embodiments, including any of the foregoing, the process includes adding an additive to the carbonation chamber.

[0117] In some embodiments, including any of the foregoing, the additive is added by injection.

[0118] In some embodiments, including any of the foregoing, the additive is added by spraying a solution of the additive into the carbonation chamber.

[0119] In some embodiments, including any of the foregoing, the process includes bubbling the conditioned gas through a solution comprising the additive.

[0120] In some embodiments, including any of the foregoing, the process occurs at 50° C. or less.

[0121] In some embodiments, including any of the foregoing, the additive is selected from the group consisting of CaCl.sub.2, CaSO.sub.4, NH.sub.4NO.sub.3, NH.sub.4Cl, and combinations thereof.

[0122] In some embodiments, including any of the foregoing, the additive is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, ammonium hydroxide, ammonium carbonate, ammonium chloride, calcium sulfate, calcium chloride, calcium nitrate, sodium carbonate, sodium bicarbonate, ammonia, trimethylamine, trimethylamine, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, alkali metal silicates, alkaline earth metal silicates, and combinations thereof.

[0123] In some embodiments, including any of the foregoing, the additive is selected from the group consisting of CaCl.sub.2, CaSO.sub.4, NH.sub.4NO.sub.3, NH.sub.4Cl, and combinations thereof.

[0124] In some embodiments, including any of the foregoing, the additive is CaCl.sub.2.

[0125] In some embodiments, including any of the foregoing, the additive is CaSO.sub.4.

[0126] In some embodiments, including any of the foregoing, the additive is NH.sub.4NO.sub.3.

[0127] In some embodiments, including any of the foregoing, the additive is NH.sub.4Cl.

[0128] In some embodiments, including any of the foregoing, the additive is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, ammonium hydroxide, ammonium carbonate, ammonium chloride, calcium sulfate, calcium chloride, calcium nitrate, sodium carbonate, sodium bicarbonate, ammonia, trimethylamine, trimethylamine, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, alkali metal silicates, alkaline earth metal silicates, and combinations thereof.

[0129] In some embodiments, including any of the foregoing, the additive is sodium hydroxide. In some embodiments, including any of the foregoing, the additive is potassium hydroxide. In some embodiments, including any of the foregoing, the additive is lithium hydroxide. In some embodiments, including any of the foregoing, the additive is calcium hydroxide. In some embodiments, including any of the foregoing, the additive is magnesium hydroxide. In some embodiments, including any of the foregoing, the additive is ammonium hydroxide. In some embodiments, including any of the foregoing, the additive is ammonium carbonate. In some embodiments, including any of the foregoing, the additive is ammonium chloride. In some embodiments, including any of the foregoing, the additive is calcium sulfate. In some embodiments, including any of the foregoing, the additive is calcium chloride. In some embodiments, including any of the foregoing, the additive is calcium nitrate. In some embodiments, including any of the foregoing, the additive is sodium carbonate. In some embodiments, including any of the foregoing, the additive is sodium bicarbonate. In some embodiments, including any of the foregoing, the additive is ammonia. In some embodiments, including any of the foregoing, the additive is trimethylamine. In some embodiments, including any of the foregoing, the additive is trimethylamine. In some embodiments, including any of the foregoing, the additive is monoethanolamine. In some embodiments, including any of the foregoing, the additive is diethanolamine. In some embodiments, including any of the foregoing, the additive is triethanolamine. In some embodiments, including any of the foregoing, the additive is isopropanolamine. In some embodiments, including any of the foregoing, the additive is diisopropanolamine. In some embodiments, including any of the foregoing, the additive is triisopropanolamine. In some embodiments, including any of the foregoing, the additive is alkali metal silicates. In some embodiments, including any of the foregoing, the additive is alkaline earth metal silicates.

[0130] In some embodiments, set forth herein is a gas processing system for integrating biomass combustion apparatus comprises: a biomass equipment apparatus integrated into a carbonation reactor and a gas processing apparatus comprising a heat exchanger and a condenser; wherein the gas processing apparatus is integrated into the biomass equipment apparatus and into the carbonation reactor; to condition CO.sub.2-containing flue gas.

[0131] In some embodiments, including any of the foregoing, the heat exchanger is selected from a gas-gas, water-gas heat exchangers, or a combination thereof.

[0132] In some embodiments, including any of the foregoing, the condenser is stainless steel or a corrosion-resistant alloy.

[0133] In some embodiments, including any of the foregoing, the gas processing system further includes a cyclone, baghouse filter, electrostatic precipitator, or a combination thereof.

[0134] In some embodiments, including any of the foregoing, the heat exchanger comprises an air-cooled or water-cooled chiller.

[0135] In yet other embodiments, the process occurs in a rotating or stirring carbonation reactor. In these embodiments, the process occurs in an aqueous/slurry. In the aqueous/slurry process, the CO.sub.2-containing flue gas stream from biomass combustion apparatus flows through a slurry or aqueous solution of solid alkaline-rich mineral material which is being stirred or rotated.

EXAMPLES

[0136] All of the carbonated concrete masonry units produced during field testing (in Example 1) would be hollow concrete masonry units having nominal dimensions of 8×8×16 inches. (203×203×406 mm) and specified dimensions of 7.625×7.625×15.625 inches. (194×194×387 mm). Concrete units would be tested to verify compliance with ASTM C90-14, Standard Specification for Loadbearing Concrete Masonry Units. Compressive strength, absorption, density, and dimensional tolerances were determined in accordance with ASTM C140/C140M-15, Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units. Linear drying shrinkage of the carbonated blocks would be evaluated in accordance with ASTM C426-16, Standard Test Method for Linear Drying Shrinkage of Concrete Masonry Units.

Example 1

Carbonation Curing Using Biomass CO.SUB.2.-Prophetic Example

[0137] This Example shows how field testing would be performed on carbonated concrete components using integrated biomass combustion equipment at a pilot plant.

[0138] A pilot carbonation chamber would be fabricated and set up at a concrete block facility to formulate and produce concrete blocks and contact with biomass-derived CO.sub.2 gas stream.

[0139] The performance of carbonated concrete blocks would be evaluated to verify their compliance with industry standards for use in construction applications. The density, water absorption, compressive strength, and CO.sub.2 uptake of carbonated concrete blocks would be measured.

Example 2

Carbonation Curing As A Function Of Moisture Content—Prophetic Example

[0140] This Example shows the effect of the moisture content of biomass feedstock on gas processing energy demand and the performance of carbonated concrete.,

[0141] Biomass resources at varying moisture contents would be provided. A dryer would be used to adjust the moisture content of biomass feedstock.

[0142] A pilot carbonation chamber would be fabricated and set up at a concrete block facility to formulate and produce concrete blocks and contact the same with biomass-derived CO.sub.2 gas stream.

[0143] The performance of carbonated concrete blocks would be evaluated to verify their compliance with industry standards for use in construction applications. The density, water absorption, compressive strength, and CO.sub.2 uptake of carbonated concrete blocks would be measured.

Example 3

Prophetic Example

[0144] This Example shows how to quantify the carbonate content of carbonated mineral materials.

[0145] Thermogravimetric analysis (TGA) would be used to assess the carbonation extent and CO.sub.2 uptake of materials before and after the mechanochemical process. Around 50 mg of powder would be extracted from finished concrete products and heated from 35° C. to 975° C. at a rate of 15° C./min in aluminum oxide crucibles under ultra-high purity N.sub.2 gas purge at a flow rate of 20 mL/min. The carbonate content would be quantified by assessing the mass loss associated with CaCO.sub.3 decomposition over the temperature range of 550° C. to 950° C. It should be noted that the CO.sub.2 uptake would account for the initial quantity of carbonates that are present in the mineral materials prior to the mechanochemical process.

Example 4

Conditioning Flue Gas Stream from Biomass Combustion System Using Gas Processing System for CO.SUB.2 .Mineralization Process—Empirical Example

[0146] This example shows the conditioning of CO.sub.2-containing flue gas stream from a biomass combustion system. A 500-kW (1,700,000 btu/hr) biomass hot air combustion system was installed at a concrete block manufacturing facility (FIG. 4). The gas processing system was designed, fabricated, and integrated into a biomass combustion system to condition flue gas in terms of temperature, relative humidity, and flow rate before entering the carbonation curing chambers. The gas conditioning system included a scrubber to remove particulate matter, a condenser to cool flue gas to remove water to target relative humidity, a heat exchanger to heat up flue gas to the target temperature, and fans to adjust the flow of flue gas before going into the carbonation curing chambers. The block flow diagram of integrated biomass combustion-carbonation system is shown in FIG. 3. The biomass flue gas composition (volume fraction) from the discharge outlet, of the biomass combustion apparatus, was measured and is presented in Table 1. The trend of biomass flue gas CO.sub.2 concentration (vol %) over the cycle of 12 hours at discharge outlet is shown in FIG. 5. The discharge outlet of the biomass combustion apparatus is the outlet directly attached to the biomass combustion apparatus. CO.sub.2 emitted from the biomass combustion apparatus exits through the discharge outlet and then enters the gas conditioning apparatus, and then, after the gas conditioning apparatus, into the carbonation chamber.

TABLE-US-00001 TABLE 1 Gas Composition as Discharge Outlet Low Medium High O2 5.82 5.00 4.000019 CO2 11.59 13.01 13.84826 SO2 0.00 0.00 0.001022 NO2 0.01 0.01 0.014032 H2O 14.65 12.56 13.23506 N2 67.93 69.42 68.9016 CO <500 ppm <500 ppm <500 ppm 100.00 100.00 100

[0147] Biomass waste wood chips were used as a fuel feedstock. The initial moisture content of woodchips was around 75 percent by weight (wt %). Woodchips were dried in a drier using hot air generated by a biomass combustion system to reduce the moisture content to around 30%. The dried wood chips were then fed into a biomass combustion system to generate CO.sub.2-containing flue gas and superheated air.

[0148] Biomass CO.sub.2-containing flue gas stream was initially passed through a scrubbing system to reduce particulate matter concentration from 350-400 mg/nm.sup.3 to about 35-70 mg/nm.sup.3. After the scrubbing process, the biomass CO.sub.2-containing flue gas stream was passed through a condenser to cool and dehumidify the flue gas stream to adjust relative humidity content. The cooled flue gas stream was then passed through heat exchangers to heat up the flue gas to the target temperature before entering the carbonation curing chambers. If additional heat was needed, an electric duct heater was used to further boost the flue gas temperature. Biomass CO.sub.2-containing flue gas stream was conditioned at T=30-80° C. (85-175° F.) and RH=20%-90% and flow rates between 100-3000 scfm before entering carbonation curing chambers comprising concrete blocks. FIG. 6 shows the representative plot of temperature conditioning of biomass flue gas through gas processing system comprising condenser and heat exchanger. In FIG. 6, the x-axis represents Time, and the y-axis represents temperature (in degrees Fahrenheit). Label TT_01.Val, on the top, is the temperature recorded for the CO.sub.2-containing gas emitted at the biomass combustion apparatus discharge outlet. Label TT_07.Val, on the bottom, is the temperature recorded for the flue gas after the condenser in the gas conditioning apparatus. Label TT_03.Val, in the middle, is the temperature recorded for the conditioned gas containing CO.sub.2 at the inlet to the carbonation chamber.

Example 5

Field Testing of Carbonated Concrete Blocks Using Direct Biomass Derived CO.SUB.2 .Containing Flue Gas Stream at Block Manufacturing Facility—Empirical Example

[0149] This pilot-testing example demonstrated the carbonation curing of concrete blocks produced via a CO.sub.2-containing flue gas stream from a biomass combustion system at ambient pressure and low temperature ranging from 20° C. to 100° C. without any additional CO.sub.2 enrichment process. The conditioned flue gas stream from the gas conditioning system was passed through a carbonation curing reactor and contacted with concrete blocks. Conditioned gas properties are as set forth in the preceding paragraph (paragraph [000131]).

[0150] Concrete blocks were produced and placed in a carbonation reactor and contacted with CO.sub.2-containing flue gas stream from the biomass combustion system. All the carbonated concrete masonry units produced during field testing were hollow concrete masonry units having nominal dimensions of 8×8×16 inches. (103×103×406 mm) and specified dimensions of 7.625×7.625×15.625 inches (194×194×387 mm).

[0151] Thermogravimetric analysis (TGA; STA 6000, Perkin Elmer) was used to assess the extent of carbonation experienced by the powder reactants. Around 40 mg of post-carbonation/hydration powder was heated from 35° C. to 975° C. at 15° C./min in an aluminum oxide crucible and under a 20 mL/min ultra-high purity N.sub.2 purge. The CO.sub.2 uptake of the concrete block was quantified by assessing the mass loss from the post-carbonation/hydration powder that is associated with CaCO.sub.3 decomposition over the temperature range from 550° C. to 900° C., normalized by the mass of the initially dry powder placed in the TGA.

[0152] The concrete blocks featured a CO.sub.2 uptake of around 1.45% to 2.2% by total solid mass and compressive strength ranging from 1600 pounds-per-square-inch (PSI) to 2100 PSI after twenty (20) hours of carbonation curing. The resulting strength gain is mainly attributed to combined carbonation-hydration reactions. The difference between CO.sub.2 concentration trends at inlet and outlet of carbonation curing reactor comprising concrete blocks is shown in FIG. 7. The average CO.sub.2 conversion efficiency over the period of the carbonation cycle ranged from 50% to about 85%. Label AE_01.val, on the top, represents the CO.sub.2 concentration of the CO.sub.2-containing flue gas emitted at the discharge outlet of the biomass combustion apparatus. Label AE_04.val, on the bottom, represents the CO.sub.2 concentration of the CO.sub.2-containing flue gas emitted at the discharge outlet of the carbonation chamber. The CO.sub.2 concentration of the CO.sub.2-containing flue gas does not change as it moves through the gas processing apparatus. However, the reduction in CO.sub.2 concentration shown by the difference between the plot at label AE_01.val and the plot at AE_04.val is attributable to the CO.sub.2 sequestered by carbonation reactions that occurred in the carbonation reactor.

[0153] For comparison, similar concrete blocks were cast and cured under air curing at a similar temperature and relative humidity without exposure to a CO.sub.2-containing flue gas stream from biomass combustion system. The uncarbonated concrete blocks indicated a compressive strength ranging from 750 psi to 1000 psi after 20 hours of air curing.

[0154] This example highlights the effectiveness of CO.sub.2 sequestration via mineral carbonation even under dilute CO.sub.2-containing flue gas streams of lower than 15 vol % from biomass combustion systems to produce low-carbon concrete materials at low temperature and ambient pressure without any additional CO.sub.2 enrichment/capture process. The integration of biomass combustion system into the CO.sub.2 mineralization system enables permanent storage of CO.sub.2 via mineral carbonation in concrete or construction material and thereby significantly reducing CO.sub.2 emission and particulate matter in the biomass combustion systems.

[0155] The embodiments and examples described above are intended to be merely illustrative and non-limiting. Those skilled in the art will recognize or will be able to ascertain using no more than routine experimentation, numerous equivalents of specific compounds, materials and procedures. All such equivalents are considered to be within the scope and are encompassed by the appended claims. In particular, while certain methods may have been described with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the disclosure. Accordingly, unless specifically indicated herein, the order and grouping of the operations is not a limitation of the disclosure. It should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the disclosure as defined by the appended claims. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, method, operation or operations, to the objective, spirit and scope of the disclosure. All such modifications are intended to be within the scope of the claims appended hereto.