JP2011524253A - Methods and systems for utilizing metal oxide waste sources - Google Patents

Abstract

A method is provided for producing a composition comprising carbonate, including utilizing a metal oxide waste source. When an aqueous solution of divalent cations (some or all of which is obtained from a metal oxide waste source) is contacted with CO2 and placed in precipitation conditions, a composition comprising carbonate can be obtained. In some embodiments, combustion ash is a metal oxide waste source for aqueous solutions containing divalent cations. In some embodiments, combustion ash is used to provide a source of proton scavenger, divalent cation, silica, metal oxide, or other desired component, or combinations thereof.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is based on U.S. Provisional Application No. 61 / 073,319 (filing date, June 17, 2008) and U.S. Provisional Application No. 61 / 079,790 (filing date). , Jul. 10, 2008) (the above application is incorporated herein by reference). This application is further a continuation-in-part of US patent application Ser. No. 12 / 344,019 (filing date, December 24, 2008), which is incorporated herein by reference in its entirety. , Claim priority in accordance with Section 120 of the US Patent Act.

  Carbon dioxide (CO2) emissions have been regarded as a major cause of global warming. CO2 is a by-product of combustion, causing operational problems, economic problems, and environmental problems. Increasing atmospheric concentrations of CO2 and other greenhouse gases are expected to increase the accumulation of heat in the atmosphere, leading to increased surface temperatures and rapid climate change. Furthermore, when the level of CO2 in the atmosphere increases, it is expected that the oceans around the world will be further acidified because CO2 dissolves and carbon dioxide is produced. The effects of climate change and ocean acidification will be costly and environmentally dangerous unless timely measures are taken. To control the potential risks from climate change, it will be necessary to contain and eliminate CO2 from various human processes.

Provided is contacting an aqueous solution with a source of metal oxide from an industrial process; charging the aqueous solution with carbon dioxide from a source of carbon dioxide from an industrial process; and bringing the aqueous solution to atmospheric pressure Subjecting to precipitation conditions below to produce a carbonate-containing precipitation material. In some embodiments, the metal oxide source and the carbon dioxide source are from the same industrial process. In some embodiments, contacting the aqueous solution with a source of metal oxide is performed prior to charging the aqueous solution with a source of carbon dioxide. In some embodiments, contacting the aqueous solution with a source of metal oxide is performed simultaneously with charging the aqueous solution with a source of carbon dioxide. In some embodiments, contacting the aqueous solution with a source of metal oxide, charging the aqueous solution with a source of carbon dioxide, and subjecting the aqueous solution to precipitation conditions are performed simultaneously. . In some embodiments, the metal oxide source and the carbon dioxide source are sourced from the same waste stream. In some embodiments, the waste stream is flue gas from a coal-fired power plant. In some embodiments, the coal-fired power plant is a lignite-fired power plant. In some embodiments, the waste stream is kiln emissions from a cement plant. In some embodiments, the metal oxide source is fly ash. In some embodiments, the metal oxide source is cement kiln dust. In some embodiments, the waste stream further includes SOx, NOx, mercury, or various combinations thereof. In some embodiments, the source of metal oxide further provides a divalent cation for generating a precipitated material. In some embodiments, both the metal oxide source and the aqueous solution include a divalent cation to produce a precipitated material. In some embodiments, the metal oxide source is fly ash or cement kiln dust. In some embodiments, the aqueous solution comprises brine, seawater, or fresh water. In some embodiments, the divalent cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof. In some embodiments, the source of metal oxide provides a proton scavenger to produce a precipitated material. In some embodiments, the source of metal oxide hydrates CaO, MgO, or a combination thereof in the aqueous solution to provide a proton scavenger. In some embodiments, the source of metal oxide further provides silica. In some embodiments, the source of metal oxide further provides alumina. In some embodiments, the source of metal oxide further provides ferric oxide. In some embodiments, red mud or brown mud from bauxite processing also provides a proton scavenger. In some embodiments, electrochemical methods that affect proton removal further provide for the formation of precipitated material.

  In some embodiments, the method further includes separating the precipitated material from the aqueous solution in which the precipitated material is produced. In some embodiments, the precipitated material comprises CaCO3. In some embodiments, CaCO3 comprises calcite, aragonite, vaterite, or combinations thereof. In some embodiments, the precipitation material further comprises MgCO3. In some embodiments, the CaCO3 includes halo stones and the MgCO3 includes neskehonite. In some embodiments, the method includes processing the precipitated material to form a building material. In some embodiments, the building material is hydraulic cement. In some embodiments, the building material is pozzolanic cement. In some embodiments, the building material is aggregate.

Further provided is the step of contacting the aqueous solution with a waste stream comprising carbon dioxide and a source comprising a metal oxide, and subjecting the aqueous solution to precipitation conditions to produce a carbonate-containing precipitated material. Is the method. In some embodiments, the waste stream is flue gas from a coal-fired power plant. In some embodiments, the coal-fired power plant is a lignite-fired power plant. In some embodiments, the metal oxide source is fly ash. In some embodiments, the waste stream is kiln emissions from a cement plant. In some embodiments, the metal oxide source is cement kiln dust. In some embodiments, the waste stream further includes SOx, NOx, mercury, or various combinations thereof. In some embodiments, the divalent cation for generating the precipitated material is provided by a source of metal oxide, an aqueous solution, or a combination thereof. In some embodiments, the aqueous solution comprises brine, seawater, or fresh water. In some embodiments, the divalent cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof. In some embodiments, the source of metal oxide further provides a proton scavenger for generating a precipitated material. In some embodiments, the source of metal oxide hydrates CaO, MgO, or a combination thereof in the aqueous solution to provide a proton scavenger. In some embodiments, the source of metal oxide further provides silica. In some embodiments, the source of metal oxide further provides alumina. In some embodiments, the source of metal oxide further provides ferric oxide. In some embodiments, red mud or brown mud from bauxite processing also provides a proton scavenger. In some embodiments, electrochemical methods that affect proton removal further provide for the formation of precipitated material. In some embodiments, the precipitated material comprises CaCO3. In some embodiments, CaCO3 comprises calcite, aragonite, vaterite, or combinations thereof. In some embodiments, the method further includes separating the precipitated material from the aqueous solution in which the precipitated material is produced. In some embodiments, the method includes processing the precipitated material to form a building material. In some embodiments, the building material is hydraulic cement. In some embodiments, the building material is pozzolanic cement. In some embodiments, the building material is aggregate.

  Further provided is a siliceous composition comprising synthetic calcium carbonate, wherein the calcium carbonate is present in at least two forms selected from calcite, aragonite, and vaterite. In some embodiments, the at least two forms of calcium carbonate are calcite and aragonite. In some embodiments, calcite and aragonite are present in a ratio of 20: 1. In some embodiments, the calcium carbonate and silica are present in a ratio of at least 1: 2 carbonate to silica. In some embodiments, 75% of the silica is amorphous silica with a particle size of less than 45 microns. In some embodiments, the silica particles are wholly or partially encapsulated by synthetic calcium carbonate or synthetic magnesium carbonate.

  Further provided is a siliceous composition comprising synthetic calcium carbonate and synthetic magnesium carbonate, wherein the calcium carbonate is present in at least one form selected from calcite, aragonite, and vaterite, Here, the magnesium carbonate is present in at least one form selected from neskehonite, magnesite, and hydromagnesite. In some embodiments, the calcium carbonate is present as olivine and the magnesium carbonate is present as neskehonite. In some embodiments, the silica is 20% or less of the siliceous composition. In some embodiments, the silica is 10% or less of the siliceous composition. In some embodiments, the silica particles are wholly or partially encapsulated by synthetic calcium carbonate or synthetic magnesium carbonate.

  Further provided is a system that includes a lime slaker, a precipitation reactor, and a liquid-solid separator adapted to sterilize a metal oxide waste source, wherein the precipitation reaction The machine is operably connected to both the lime slaker and the liquid-solid separator, further wherein the system is configured to produce carbonate-containing precipitated material in an amount greater than 1 ton / day. Yes. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 10 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 100 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 1000 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 10,000 tons / day. In some embodiments, the lime slaker is selected from a slurry stay lime slaker, a paste lime slaker, and a ball mill lime slaker. In some embodiments, the system further includes a source of carbon dioxide. In some embodiments, the carbon dioxide source is from a coal-fired power plant or a cement plant. In some embodiments, the system further includes a source of proton scavenger. In some embodiments, the system further includes a source of divalent cations. In some embodiments, the system further includes a building material generation unit configured to generate building material from the solid product of the liquid-solid separator.

  The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that refers to the illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: That would be true.

1 is a schematic diagram of an example of a power plant flue gas treatment process using ESP and FGD. FIG. 1 is a schematic diagram of an example power plant flue gas treatment process utilizing an embodiment of the present invention. FIG. 2 is a SEM image of the precipitated material of Example 2 magnified 1000, 2500, and 6000 times. 2 is an XRD for the precipitated material of Example 2. 2 is a TGA for the precipitated material of Example 2. It is a SEM image which expanded the precipitation substance of Example 3 2500 times. 3 is an XRD of the precipitated material of Example 3. 2 is a TGA of the precipitated material of Example 3. 4 is an SEM image of the oven-dried precipitated material of Example 4 magnified 2,500 times. 4 is an FT-IR of the oven-dried precipitated material of Example 4.

  Before describing the present invention in further detail, it is to be understood that the present invention is not limited to the specific embodiments described, and, of course, modifications may be made. Furthermore, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, the scope of the invention being defined by the appended claims. It should also be understood that it will only be limited.

  If a numerical value is given as a range, each intermediate value that falls between the upper and lower limits of the range (10 minutes of the lower limit unit) unless the context clearly indicates otherwise. 1) and any other defined numerical value or intermediate value within the defined range should be understood to be included in the present invention. The upper and lower limits of these narrower ranges may be independently included within the narrower range, and accordingly, according to any specially excluded limits within the defined ranges, this also applies to the present invention. Included in. Where the stated range includes limits in one or both, ranges over either or both of those included limits are also included in the invention.

  In the present specification, certain ranges are expressed using numerical values with the antecedent “about”. In this specification, the term “about” is used to provide literal support for the exact number that follows it, and even in the vicinity of or approximately to the number that follows the term. Has been. In determining whether a number is in the vicinity or approximate number of a clearly stated number, an unrewarded number that is in or near that number is in the context in which it is expressed. It may be a number that is substantially equivalent to the clearly described number.

  Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, exemplary methods and materials for illustration The substance will be described below.

  All publications, patents, and patent applications cited in this specification are to the same extent as if each individual publication, patent, or patent application was expressly and individually incorporated by reference. And incorporated herein by reference. In addition, each cited publication, patent, or patent application is cited and incorporated herein by reference for the purpose of disclosing and describing the subject matter in relation to what the publication was cited. Citation of any publication is because it was disclosed prior to the filing date of this application, and was cited herein as if such publication had previously been made by the prior invention. You must not accept that the present invention allows you to be entitled. In addition, the published date of publication may be different from the actual published date, which must be confirmed individually.

  As used herein and in the appended claims, the singular forms “a”, “an” and “the” include plural unless the context clearly dictates otherwise. Note that the nuances are included. It should also be noted that the claims may be drafted to exclude any optional element. Therefore, this wording is used in connection with the description of the components of the claims to use exclusive terms such as “solely” and “only”, or “passive” It is intended to serve as a preliminary basis for using the limitation.

  After reading this disclosure, it will be apparent to one skilled in the art that each of the individual embodiments described and described herein can be easily accomplished without departing from the scope and spirit of the present invention. Individual features and features that can be separated from or combined with features of any of these embodiments. Any of the described methods can be performed in the order of events described, or in any other order as long as it is logically possible.

Materials As described in more detail below, the present invention utilizes a source of CO2, a source of proton scavenger (and / or a method that causes proton removal), and a source of divalent cations. Metal oxide waste sources (eg, combustion ash, eg fly ash, bottom ash, boiler slag; cement kiln dust; and slag, eg iron slag and phosphorus slag), in whole or in part, supply of proton removers Source and / or source of divalent cations can be provided. Accordingly, metal oxide waste sources such as combustion ash (eg, fly ash, bottom ash, boiler slag), cement kiln dust, and slag (eg, iron slag, phosphorus slag) are compositions described herein. Can be a single source of divalent metal cations and proton scavengers for the preparation of Waste sources such as ash, cement kiln dust, slag (eg, iron slag, phosphorus slag) may also be used in combination with an auxiliary source of divalent cations or proton scavengers. A source of carbon dioxide, an auxiliary divalent cation source, and an auxiliary proton removal source (and a method for causing proton removal) will be described first as a source of divalent cation and proton remover. Let us explain the situation for the metal oxide waste sources. Subsequently, metal oxide waste sources such as combustion ash, cement kiln dust, and slag (eg, iron slag, phosphorus slag) are described, followed by these metal oxide waste sources. A method for using to produce a composition containing carbonate is described.

Carbon dioxide The method of the present invention includes contacting a volume of an aqueous solution of a divalent cation with a source of CO2, and then subjecting the resulting solution to precipitation conditions. There should be sufficient carbon dioxide in the divalent cation-containing solution to precipitate a sufficient amount of carbonate-containing precipitation material (eg, from seawater), but usually additional carbon dioxide is used. . The CO2 source may be any convenient CO2 source. The CO2 source may be a gas, liquid, solid (eg, dry ice), supercritical fluid, or CO2 dissolved in a liquid. In some embodiments, the CO2 source is a gaseous CO2 source. The gaseous stream may be substantially pure CO2 or a plurality comprising CO2 and one or more additional gases and / or other substances such as ash or other particulates. Ingredients may be included. In some embodiments, the gaseous CO2 source is a waste feed (i.e., a byproduct of an industrial plant production process), such as emissions from an industrial plant. The types of industrial plants can be varied and include (but are not limited to) the following industrial plants: power plants, chemical processing plants, machining plants, refineries, cement Plants, steel plants, and other industrial plants where CO2 is produced as a by-product of fuel combustion or other processing processes (eg, calcination by cement plants).

  Waste gas streams containing CO2 include both reducing conditioned streams (eg, syngas, shifted syngas, natural gas, hydrogen, etc.) and oxidative conditioned streams (eg, flue gas from combustion). included. Specific waste gas streams that may be advantageous for the present invention include: Oxygen-containing combustion industrial plant flue gas (eg, coal or other carbon systems, with little or no flue gas pretreatment) Not at all), turbocharge boiler product gas, coal gasification product gas, shifted coal gasification product gas, anaerobic digester product gas, wellhead natural gas stream, reformed natural gas, methane hydrate, etc. . Combustion gases from a variety of convenient sources can be used in the methods and systems of the present invention. In some embodiments, combustion gases are used in post-combustion exhaust stacks of industrial plants such as power plants, cement plants, and coal processing plants.

  Accordingly, the waste stream may be generated from various types of industrial plants. Suitable waste streams in the present invention include anthropogenic fuel products from fossil fuels (eg, coal, petroleum, natural gas) and naturally derived organic fuel deposits (eg, tar sands, heavy oil, oil shale, etc.) Waste stream produced in an industrial plant that burns. In some embodiments, waste streams suitable for the systems and methods of the present invention are coal-fired power plants, such as pulverized coal power plants, supercritical coal power plants, mass burning coal power plants, fluidized bed coal power plants. And in some embodiments, the waste stream is gas or heavy oil fired boiler and steam turbine power plant, gas or heavy oil fired boiler simple cycle gas turbine power plant, or gas or The power source is a cycle gas turbine power plant combined with a heavy oil combustion boiler. In some embodiments, a waste stream produced by a power plant that burns synthesis gas (ie, gas produced by gasification of organic materials such as coal, biomass, etc.) is used. In some embodiments, a waste stream from an integrated gasification combined cycle (IGCC) plant is used. In some embodiments, waste streams produced by a Heat Recovery Steam Generator (HRSG) plant are used to produce aggregates according to the systems and methods of the present invention.

  Waste streams produced by cement plants are also suitable for the system and method of the present invention. Cement plant waste streams include waste streams from both wet and dry process plants, which may employ shaft kilns or rotary kilns and include pre-calcining furnaces. It may be. Each of these industrial plants may burn a single fuel, or may burn two or more fuels sequentially or simultaneously.

  Industrial waste gas streams may contain carbon dioxide as the main non-air-derived component, or in the case of coal-fired thermal power plants in particular, additional components such as nitrogen oxides (NOx), sulfur An oxide (SOx) and one or more additional gases may be included. Additional gases and other components include CO, mercury and other heavy metals, and dust particles (eg, from calcination and combustion processes). Other components in the gas stream further include halides such as hydrogen chloride and hydrogen fluoride, particulate matter such as fly ash, dust, and metals such as arsenic, beryllium, boron, cadmium, chromium, chromium VI, cobalt, lead, Examples include manganese, mercury, molybdenum, selenium, strontium, thallium, and vanadium, and organic substances such as hydrocarbons, dioxins, and PAH compounds. Suitable gaseous waste streams that can be treated include, in some embodiments, the amount of CO2 present is 200 ppm to 1,000,000 ppm, 200,000 ppm to 1000 ppm, 200, 000 ppm to 2000 ppm, 180,000 ppm to 2000 ppm, 180,000 ppm to 5000 ppm, or 180,000 ppm to 10,000 ppm. Waste streams, particularly waste streams of various combustion gases, include one or more additional components such as water, NOx (mononitrogen oxides: NO and NO2), SOx (monosulfur oxides: SO, SO2). And SO3), VOC (volatile organic compounds), heavy metals such as mercury, and particulate matter (solid or liquid particles suspended in a gas). The temperature of the flue gas is also variable. In some embodiments, the flue gas temperature is from 0C to 2000C, such as from 60C to 700C, such as from 100C to 400C.

In various embodiments, one or more additional components contact a waste gas stream that includes those additional components with an aqueous solution that includes divalent cations (eg, alkaline earth metal ions such as Ca ²⁺ and Mg ²⁺ ). To precipitate in the precipitated material formed. Calcium and magnesium sulfates and / or sulfites may be precipitated into a precipitation material (further comprising calcium carbonate and / or magnesium carbonate) generated from a waste gas stream comprising SOx (eg, SO ₂ ). . Magnesium and calcium react to form CaSO 4, MgSO 4, and other calcium- and magnesium-containing compounds (eg, sulfites) without the need for desulfurization processes such as flue gas desulfurization (“FGD”) However, sulfur can be efficiently removed from the flue gas stream. Furthermore, CaCO3, MgCO3, and related compounds can be formed without further release of CO2. If the aqueous solution of the divalent cation contains high levels of sulfur compounds (eg, sulfate), increasing the calcium and magnesium content of the aqueous solution produces CaSO4, MgSO4, and related compounds. After or in addition to their production, calcium and magnesium may be made available to form carbonate compounds. In some embodiments, the desulfurization step may be consistent with the precipitation of the carbonate-containing precipitation material, or the desulfurization step may be placed before precipitation occurs. In some embodiments, multiple reaction products (eg, carbonate-containing precipitation material, CaSO 4, etc.) are collected in different steps, whereas in other embodiments, a single reaction is collected. Product (eg, precipitated material including carbonates, sulfates, etc.) is collected. In the process involving these embodiments, other components such as heavy metals (eg, mercury, mercury salts, mercury-containing compounds) may be trapped in the carbonate-containing precipitation material, or separately precipitated. May be.

  A portion of the gaseous waste stream from the industrial plant (ie, not all of the gaseous waste stream) may be used to produce the precipitated material. In these embodiments, the percentage of gaseous waste stream employed to precipitate the precipitated material should be 75% or less, such as 60% or less, such as 50% or less, of the gaseous waste stream. Good. In yet another embodiment, substantially all (eg, 80% or more) of the gaseous waste stream produced by the industrial plant is used to precipitate the precipitated material. In these embodiments, 80% or more, for example 90% or more, for example 95% or more, up to 100% of the gaseous waste stream (eg flue gas) produced at the source is precipitated May be used to

  In industrial waste gas, a relatively concentrated source of combustion gas is provided, but the method and system of the present invention further provides a enrichment that includes a much lower concentration of contaminants than, for example, flue gas. It can also be applied to remove combustion gas components from lower sources (eg, the atmosphere). Accordingly, in some embodiments, the methods and systems include reducing the concentration of pollutants in the atmosphere by producing a stable precipitated material. In these cases, the concentration of pollutants, such as CO2, as a proportion in the atmosphere, is 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% As mentioned above, it can be reduced by 90% or more, 95% or more, 99% or more, 99.9% or more, or 99.99%. Such a reduction in air pollutants can be achieved in yields as described herein, or in higher or lower yields, although it can be achieved in a single precipitation step, even if a series of precipitation steps. May be achieved.

Divalent cations As mentioned above, metal oxide waste sources such as combustion ash (eg fly ash, bottom ash, boiler slag), cement kiln dust, and slag (eg iron slag, phosphorus slag) (for each of them) Are described in more detail in the respective sections below), but may be a single source of divalent metal cations for preparing the compositions described herein, such as ash, cement kiln Waste sources such as dust, slag (eg, iron slag, phosphorus slag) may be used in combination with an auxiliary source of divalent cations described in this section.

  The method of the present invention includes contacting a volume of an aqueous solution of a divalent cation with a source of CO2, and placing the resulting solution in precipitation conditions. In addition to the divalent cation waste source, divalent cations may be obtained from a number of different divalent cation sources, depending on availability at a particular location. Such sources include industrial waste, seawater, brine, hard water, minerals, and various other suitable sources.

  In some locations, industrial waste streams from various industrial processes are a convenient source of divalent cations (and possibly other materials useful in the process, such as metal hydroxides). give. Such waste streams include (but are not limited to): mining waste; fossil fuel combustion ash (eg, fly ash, as described in more detail herein). Slag (eg, iron slag, phosphorus slag); cement kiln waste (described in more detail herein); refinery / petroleum refinery waste (eg oil field and methane bed brine); coal bed waste (eg Paper processing waste; softening waste brine (eg, ion exchange effluent); silicon processing waste; agricultural waste; metal finishing waste; high pH textile waste; and caustic Sludge.

In some places, a convenient source of divalent cations for use in the systems and methods of the present invention is water (eg, an aqueous solution containing divalent cations, such as sea water or surface brine), It may vary depending on the particular location where the present invention is implemented. Suitable aqueous solutions of divalent cations that can be used include solutions containing one or more divalent cations, for example alkaline earth metal cations such as Ca ²⁺ and Mg ²⁺ . In some embodiments, the aqueous solution of the divalent cation source includes an alkaline earth metal cation. In some embodiments, the alkaline earth metal cation includes calcium, magnesium, or a mixture thereof. In some embodiments, the divalent cation aqueous solution contains calcium in an amount of 50 to 50,000 ppm, 50 to 40,000 ppm, 50 to 20,000 ppm, 100 to 10,000 ppm, 200 to 5000 ppm, or 400 to Included in amounts in the range of 1000 ppm. In some embodiments, the divalent cation aqueous solution contains magnesium in an amount of 50-40,000 ppm, 50-20,000 ppm, 100-10,000 ppm, 200-10,000 ppm, 500-5000 ppm, or 500-5000. Included in amounts ranging from 2500 ppm. In some embodiments, when both Ca ²⁺ and Mg ²⁺ are present, the ratio of Ca ²⁺ to Mg ²⁺ in the aqueous solution of the divalent cation (ie, Ca ²⁺ : Mg ²⁺ ) is: (1: 1) to (1: 2.5), (1: 2.5) to (1: 5), (1: 5) to (1:10), (1:10) to (1:25) ), (1:25) to (1:50), (1:50) to (1: 100), (1: 100) to (1: 150), (1: 150) to (1: 200), (1: 200) to (1: 250), (1: 250) to (1: 500), or (1: 500) to (1: 1000). In some embodiments, the ratio of Mg ²⁺ to Ca ²⁺ in the aqueous solution of the divalent cation (ie, Mg ²⁺ : Ca ²⁺ ) is from (1: 1) to (1: 2.5), (1 : 2.5) to (1: 5), (1: 5) to (1:10), (1:10) to (1:25), (1:25) to (1:50), (1 : 50) to (1: 100), (1: 100) to (1: 150), (1: 150) to (1: 200), (1: 200) to (1: 250), (1: 250) ) To (1: 500), or (1: 500) to (1: 1000).

  Aqueous solutions of divalent cations may contain divalent cations derived from: fresh water, brackish water, sea water, or brine (eg, naturally derived brine or artificial brine, eg, geothermal power plant wastewater, desalination) Plant wastewater), and also other salt waters having a salinity higher than that of fresh water (all of which may be naturally derived or artificial). Brackish water has a higher salinity than fresh water but does not have the same salinity as seawater. Brackish water has a salinity of about 0.5 to about 35 ppt (parts per thousand). Seawater is water from the sea, ocean, or other salt-containing water having a salinity in the range of about 35 to about 50 ppt. Brine is water that is saturated or almost saturated with salt. Brine has a salinity of about 50 ppt or more. In some embodiments, the source of salt water from which the divalent cation is derived is from a natural source selected from the sea, ocean, lake, marsh, cove, lagoon, surface brine, deep brine, alkaline lake, inland sea, etc. Is the source. In some embodiments, the source of salt water from which the divalent cations are derived is an artificial brine selected from geothermal power plant wastewater or desalted wastewater.

Fresh water is often the source of convenient divalent cations (eg, alkaline earth metals such as Ca ²⁺ and Mg ²⁺ cations). A number of suitable freshwater sources may be used, including freshwater sources ranging from relatively low mineral sources to relatively rich mineral sources. Mineral-rich fresh water sources may be naturally derived, such as various hard water sources, lakes or inland seas. Some mineral-rich freshwater sources such as alkaline lakes or inland seas (eg Lake Van, Turkey) are also sources of pH modifiers. The mineral-rich freshwater source may be artificial. For example, mineral-poor water (soft water) is contacted with a source of divalent cations such as alkaline earth metal cations (eg, Ca ²⁺ , Mg ^2+, etc.) and is suitable for the methods and systems described herein Mineral-rich water may be produced. Divalent cations or their precursors (eg, salts, minerals) can be converted into fresh water (or various other types) using various convenient procedures (eg, addition of solids, suspensions, or solutions, etc.) May be added to the water) described herein. In some embodiments, a divalent cation selected from Ca ²⁺ and Mg ²⁺ is added to fresh water. In some embodiments, a monovalent cation selected from Na ⁺ and K ⁺ is added to fresh water. In some embodiments, a solution comprising calcium and magnesium cations in combination with fresh water containing Ca ^{2+ in combination} with magnesium silicate (eg, olivine or serpentine) or a product or processed form thereof Get.

  Many minerals are sources of divalent cations, but some minerals are also sources of bases. Mafic and ultramafic minerals such as olivine, serpentine, and various other suitable minerals may be dissolved using a variety of convenient procedures. Other minerals such as wollastonite may be used. The dissolution can be accelerated by increasing the surface area, for example by means of conventional means of grinding, for example jet mill grinding, and for example ultrasonic means. In addition, mineral dissolution may be accelerated by exposure to acids or bases. Metal silicates (eg magnesium silicate) and other minerals containing the cation of interest are dissolved in an acid such as HCl (possibly from an electrochemical process) and precipitated For example, magnesium and other metal cations may be generated for use in the material. In some embodiments, magnesium silicate and other minerals are digested in an aqueous solution that has already been acidified by the addition of carbon dioxide and other components of waste gas (eg, combustion gas), or Alternatively, it may be dissolved. Alternatively, other metal species such as metal hydroxides (eg, Mg (OH) 2, Ca (OH) 2) can be replaced with alkali hydroxides (eg, NaOH) or various other suitable alkaline materials. An aqueous solution may be used by dissolving one or more metal silicates (eg, olivine and serpentine). Various suitable concentrations of aqueous alkali hydroxide or other alkaline materials may be used to decompose the metal silicate, including highly concentrated or highly dilute solutions. The (weight) concentration of alkali hydroxide (for example, NaOH) in the solution is, for example, 30% to 80%, and water is 70% to 20%. Advantageously, the precipitated material may be produced directly using a metal silicate or the like digested with an aqueous alkali hydroxide solution. Furthermore, the base value may be recovered from the precipitation reaction mixture and reused for further digestion of metal silicates and the like.

  In some embodiments, an aqueous solution of divalent cations may be obtained from an industrial plant that also provides a combustion gas stream. For example, in a water-cooled industrial plant, such as a seawater-cooled industrial plant, the water used for cooling in the industrial plant may then be used to produce the precipitated material. If desired, the water may be cooled before it is introduced into the precipitation system. Such an approach may be employed in a single pass cooling system, for example. For example, city water or agricultural water supply may be employed as a single pass cooling system for an industrial plant. The water from the industrial plant may then be used to produce the precipitated material, but the water discharged in this case has reduced hardness and increased purity. If desired, such systems can be modified to include safety measures (eg, detection of fraudulent activities such as poisoning) or to work with government agencies (eg, Homeland Security or other agencies). Good. In such embodiments, additional defenses against fraud or attacks may be employed.

Proton scavengers and methods As noted above, metal oxide waste sources such as combustion ash (eg, fly ash, bottom ash, boiler slag), cement kiln dust, and slag (eg, iron slag, phosphorus slag) Each is described in more detail in the respective sections below), but may be a single source of proton scavengers for preparing the compositions described herein, such as ash, cement kiln Using waste sources such as dust, slag (eg, iron slag, phosphorus slag) in combination with an auxiliary source of proton scavengers (and methods for producing proton removal) described in this section Also good.

  The method of the present invention includes contacting a volume of an aqueous solution of a divalent cation (to dissolve CO2) with a source of CO2, and subjecting the resulting solution to precipitation conditions. . When CO2 dissolves in an aqueous solution of a divalent cation, a species of carbonic acid is formed that is in equilibrium with both bicarbonate and carbonate. To produce a carbonate-containing precipitate, protons are removed from various species (eg, carbonate, bicarbonate, hydronium, etc.) in a divalent cation-containing solution, and the equilibrium is shifted toward the carbonate. Let As protons are removed, more CO2 enters the solution. In some embodiments, a proton scavenger and / or method is used that increases the absorption of CO2 while contacting the divalent cation-containing aqueous solution with CO2 in one phase of the precipitation reaction, with the pH being reduced. It may be kept constant, raised, or even lower, and the protons are rapidly removed (eg, by adding a base) to rapidly precipitate the carbonate-containing precipitated material. Various convenient approaches may remove protons from various chemical species (eg, carbonic acid, bicarbonate, hydronium, etc.), such as the use of naturally occurring proton removing agents. , Use of microorganisms and fungi, use of synthetic chemical proton scavengers, recovery of artificial waste streams, use of electrochemical means, and the like.

  Included in naturally occurring proton scavengers are various proton scavengers that can be found in a wider environment that creates or has a basic local environment. In some embodiments, naturally occurring proton scavengers are provided that include minerals that create a basic environment when added (ie, dissolved) to a solution. Such minerals include (but are not limited to): minerals such as lime (CaO); periclase (MgO); volcanic ash; ultramafic rocks and serpentine And hydroxideite materials (eg goethite and limonite). A method for dissolving such rocks and minerals is provided herein. In some embodiments, the use of a natural alkaline body of water as a naturally occurring proton scavenger is provided. Examples of natural alkaline aqueous bodies include (but are not limited to): surface water sources (eg, alkaline lakes, such as Mono Lake, California) and groundwater sources (eg, , Basic aquifer). In another embodiment, the use of deposits from dry alkaline aqueous objects, such as the crust along Lake Natron in Great Lift Valley, Africa, is provided. In some embodiments, organisms that excrete basic molecules or solutions in their normal metabolic action are used as proton scavengers. Examples of such organisms include fungi that produce alkaline proteases (eg, the deep-sea fungus Aspergillus ustus, optimum pH, 9) and bacteria that produce alkaline molecules (eg, cyanobacteria such as British Genus Lingbya from Atlin Wetland, Columbia, which raises the pH by photosynthesis byproducts. In some embodiments, the organism is used to generate a proton scavenger, but the organism (eg, Bacillus pasteurizing, which hydrolyzes urea to ammonia). Metabolize contaminants (eg, urea) to produce proton scavengers or solutions containing proton scavengers (eg, ammonia, ammonium hydroxide). In some embodiments, the organism is cultured separately from the precipitation reaction mixture, in which case a proton scavenger or a solution containing the proton scavenger is used to add to the precipitation reaction mixture. In some embodiments, carbon dehydrase is used as a naturally-occurring proton scavenger to remove protons, causing precipitation of the precipitated material. Carbon dehydrase, an enzyme produced by plants and animals, accelerates the conversion of carbonic acid to bicarbonate in aqueous solution.

  Chemical agents effective for proton removal are generally called synthetic chemical agents, and are produced in large quantities and are commercially available. For example, chemical agents for removing protons include, but are not limited to, hydroxides, organic bases, superbases, oxides, ammonia, and carbonates. Hydroxides include chemical species that provide hydroxide anions in solution, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca (OH) 2), or magnesium hydroxide ( Mg (OH) 2) and the like. Organic bases are carbon-containing molecules that are typically nitrogenous bases, such as primary amines such as methylamine, secondary amines such as diisopropylamine, tertiary amines such as diisopropylethylamine, aromatic amines such as aniline, heteroaromatics. Examples include pyridine, imidazole, and benzimidazole, and various forms thereof. In some embodiments, an organic base selected from pyridine, methylamine, imidazole, benzimidazole, histidine, and phophazene is used to form a species (e.g., carbonic acid, bicarbonate) to precipitate the precipitated material. Salt, hydronium, etc.) used to remove protons. In some embodiments, ammonia is used to raise the pH to a level sufficient to precipitate the precipitated material from the divalent cation and industrial waste stream solution. Superbases suitable for use as proton scavengers include sodium ethoxide, sodium amide (NaNH2), sodium hydride (NaH), butyllithium, lithium diisopropylamide, lithium diethylamide, and lithium bis (trimethylsilyl) amide. Can be mentioned. Oxides such as calcium oxide (CaO), magnesium oxide (MgO), strontium oxide (SrO), beryllium oxide (BeO), and barium oxide (BaO) are also suitable as usable proton scavengers. The carbonate used in the present invention includes, but is not limited to, sodium carbonate.

  In addition to targeted cations and other suitable metal forms, waste streams from various industrial processes may provide proton scavengers. Such waste streams include (but are not limited to): mining waste; fossil fuel combustion ash (eg, fly ash, as described in more detail herein). Slag (eg iron slag, phosphorus slag); cement kiln waste; refinery / petroleum refinery waste (eg oil field and methane bed brine); coal bed waste (eg gasification brine and coal bed brine); Paper processing waste; softening waste brine (eg, ion exchange effluent); silicon processing waste; agricultural waste; metal finishing waste; high pH textile waste; and caustic sludge. Mining waste includes various types of waste from the extraction of metals or other valuable or useful minerals from the ground. In some embodiments, waste from mining is used to adjust the pH, but the waste is red mud from the Bayer process aluminum extraction process; waste from magnesium extraction from seawater (Eg, Mg (OH) 2, such as found in Moss Landing, Calif .; and waste from mining processes including leaching. For example, US Provisional Application No. 61 / 161,369 ( Red mud may be used to adjust the pH as described in the filing date, March 18, 2009 (which is incorporated herein by reference in its entirety) Agricultural waste, whether it comes from animal waste or excessive use of chemical fertilizer, KOH) or ammonia (NH 3) or both, therefore, in some embodiments of the present invention, agricultural waste may be used as a proton scavenger. It is often collected from a pond, but if it can be collected and used, it may be leached into an aquifer.

  Electrochemical methods are yet another means for removing protons from various chemical species in a solution, either by removing protons from the solute (eg, deprotonation of carbonic acid or bicarbonate). ) Or by either removing the protons from the solvent (eg, deprotonation of hydronium or water). For example, when proton production from CO2 dissolution balances or exceeds electrochemical proton removal from solute molecules, deprotonation of the solvent occurs. Alternatively, electrochemical molecules may be used to generate alkaline molecules (eg, hydroxides), for example by the chloralkali process or a modification thereof. Electrodes (ie, cathode and anode) are present in a device containing a solution charged with a divalent cation-containing aqueous solution or gaseous waste stream (eg, charged with CO 2) and are selectively removed by a selective barrier such as a membrane. These electrodes may be separated. Electrochemical systems and methods for removing protons can produce by-products (eg, hydrogen), which may be collected and used for other applications. Additional electrochemical approaches that may be used in the systems and methods of the present invention include, but are not limited to, those described in the following patent applications: US Patent Application No. 61 / No. 081,299 and US patent application Ser. No. 61 / 091,729, the disclosures of which are incorporated herein by reference.

  In some embodiments, low voltage electrochemical methods are used to remove protons, for example because CO2 is dissolved in the precipitation reaction mixture or precursor solution to the precipitation reaction mixture. is there. The precursor solution to the precipitation mixture may or may not contain, for example, a divalent cation. In some embodiments, the carbonic acid, bicarbonate produced by dissolving CO2 in an aqueous solution free of divalent cations by a low voltage electrochemical process to dissolve the CO2. , Hydronium, or various species, or combinations thereof, remove protons. The low voltage electrochemical method is 2, 1.9, 1.8, 1.7, or 1.6V or less, such as 1.5, 1.4, 1.3, 1.2, 1.1V or less, For example, 1V or less, such as 0.9V or less, 0.8V or less, 0.7V or less, 0.6V or less, 0.5V or less, 0.4V or less, 0.3V or less, 0.2V or less, or 0.1V or less The average voltage is used. For use in the system and method of the present invention, it is advantageous to use a low voltage electrochemical method that does not generate chlorine gas. Low voltage electrochemical methods that do not generate oxygen gas to remove protons are also advantageous for use in the systems and methods of the present invention. In some embodiments, the low voltage electrochemical method generates hydrogen gas at the cathode, which is transported to the anode where it is converted to protons. An electrochemical method that does not generate hydrogen gas is also advantageous. In some cases, electrochemical methods for removing protons do not generate any gaseous by-products. See, for example, the following patent applications: U.S. Patent Application No. 12 / 344,019 (Filing Date, December 24, 2008), U.S. Patent Application No. 12 / 375,632 (Filing Date, PCT Patent Application No. PCT / US08 / 088822 (Application Date, December 23, 2008), and PCT Patent Application No. PCT / US09 / 32301 (Application Date, 2009). (January 28)), the contents of which are incorporated herein by reference in their entirety.

Combustion ash, cement kiln dust, and slag Metal oxide waste sources (eg, combustion ash, eg fly ash, cement kiln dust, etc.), the only proton removal to prepare the compositions described herein It is good also as a supply source of an agent. In other words, the only proton removal that uses metal oxide waste sources, such as combustion ash, cement kiln dust, etc., to modify the pH of the reaction mixture from which the inventive composition is formed. It is good also as a supply source of an agent. Thus, in some embodiments, the only source of proton scavenger is combustion ash selected from fly ash, bottom ash, and boiler slag. In some embodiments, the sole source of proton scavenger is cement kiln dust. In some embodiments, the only source of proton scavenger is slag (eg, iron slag, phosphorus slag). Similarly, a source of metal oxide waste (eg, combustion ash such as fly ash, cement kiln dust, etc.) is the only source of divalent metal cations for preparing the compositions described herein. It is good. In other words, metal oxide waste sources such as combustion ash, cement kiln dust, etc. may be the only source of divalent cations from which the composition of the invention is produced. Thus, in some embodiments, the only source of divalent cations is combustion ash selected from fly ash, bottom ash, and boiler slag. In some embodiments, the only source of divalent cations is cement kiln dust. In some embodiments, the only source of divalent cations is slag (eg, iron slag, phosphorus slag). In some embodiments, a metal oxide waste source (eg, combustion ash such as fly ash, cement kiln dust, etc.) is the only divalent cation and proton removal for precipitating the precipitated material according to the present invention. The source of the agent. For example, fly ash may provide both a divalent cation and a proton scavenger for precipitating the precipitated material. In addition, combining metal oxide waste sources with other sources of either divalent cations and / or proton scavengers will now be described in further detail.

  Carbonaceous fuels such as coal produce combustion ash waste products, such as fly ash, bottom ash, and boiler slag, which are often disposed of in landfills or used for low-value applications as a means of disposal. Or These waste products often contain leachable contaminants that can contaminate groundwater when landfilled. The American Coal Ash Association reports that more than 56% of the 165,000,000 tonnes of coal combustion products annually in the United States are sent to landfills at a substantial cost to coal burners. Yes. Combustion ash generated by burning fossil fuels (for example, coal in coal-fired thermal power plants) is often rich in CaO or other metal oxides, creating a basic environment, Among them, a divalent cation is given. Combustion products from coal, wood, and other sources, including volcanic ash emitted by volcanic eruptions (generally considered to be combustion ash, respectively) contain various oxides such as Also included are silica (SiO 2), alumina (Al 2 O 3), and oxides such as calcium, magnesium, iron, which promote certain chemical reactions to obtain cement. The coal ash employed in the present invention (that is, combustion ash generated by burning coal) is a power plant boiler or a coal combustion furnace (for example, chain great boiler, dry bottom pulverized coal boiler, slag tap boiler, cyclone boiler). And fluidized bed boilers) refers to ash substances produced by burning pulverized anthracite, lignite, bituminous, subbituminous, or lignite. Such coal ash includes: fly ash (which is fine coal ash carried out of the furnace by emissions or flue gas); bottom ash (which is (eg, dry (In the bottom boiler) that is collected as agglomerates at the base of the furnace); and boiler slag (which is collected in the ash hopper of the wet bottom boiler).

  High sulfur coal, which is more abundant and less expensive than low sulfur coal, typically performs flue gas desulfurization (FGD) to remove sulfur oxides (“SOx”) from flue gas emissions. There is a need. This process generally further increases CO2 emissions into the atmosphere due to the use of limestone as a reactant to produce CaSO4. This process produces high calcium fly ash due to the calcium released from the limestone in the process, where the calcium is in the form of calcium oxide (CaO). In normal power plants or industrial coal combustion facilities, flue gas pretreatment prior to atmospheric release includes electrostatic precipitating (“ESP”), wet or dry scrubbing, and flue gas desulfurization (“FGD”). )) May be included. In many FGD processes, flue gas after ESP treatment is introduced into an FGD absorption tank where it reacts with limestone slurry to form CaSO4 to remove sulfur from the flue gas. Each molecule of CaSO4 formed in this way releases CO2 molecules, further exacerbating the massive release of CO2 associated with the burning of fossil fuels such as coal.

  Fly ash is generally very inhomogeneous and includes glassy particles having various identifiable crystal phases such as quartz, mullite, hematite, magnetite, and a mixture of various iron oxides. The fly ash in question is type F and type C fly ash. Type F and Type C fly ash, referred to above, are defined in CSA Standard A23.5 and ASTM C618. The main difference between these types is the content of calcium, silica, alumina, and iron in the ash. The chemical nature of fly ash is greatly influenced by the chemical composition of the burned coal (eg, anthracite, bituminous, subbituminous, lignite, lignite). The nature of fly ash can also depend on temperature history, type of burner used, post-combustion treatment, scrubber effect, and impounding time and conditions. The subject fly ash contains substantial amounts of silica (silicon dioxide, SiO2) (both amorphous and crystalline) and lime (calcium oxide, CaO, magnesium oxide, MgO). The outer surface of fly ash is generally rich in CaO and MgO, but the concentration of CaO and MgO decreases from the outer surface of the fly ash toward the center. As CaO and MgO decrease, SiO2 increases at a commensurate concentration. The high shear mixing and wet milling used in some embodiments described below allows for greater access to all the CaO and MgO present in the fly ash. Table 1 below shows the chemical composition of various types of fly ash that can be used in embodiments of the present invention.

  Burning harder and older anthracite and bituminous coal typically produces Class F fly ash. Class F fly ash has pozzolanic properties (ie, in the presence of moisture, fine silica or aluminosilicate reacts with Ca (OH) 2 to form a compound with cement-like properties. However, silica or aluminosilicate alone has little or no cement-like properties), and the content of lime (CaO) is less than 10%. In addition to having a pozzolanic character, fly ash produced by burning younger lignite or subbituminous coal also has some self-cementing properties. In the presence of water, Class C fly ash hardens and increases in strength over time. Class C fly ash typically contains more than 20% lime (CaO). The content of alkali and sulfate (SO4) is generally higher in class C fly ash.

  The fly ash material solidifies while suspended in the exhaust gas and is collected using various approaches, such as electrostatic precipitators or filter bags. Because these particles solidify while suspended in the exhaust gas, the fly ash particles generally have a spherical shape and a size in the range of 0.5 μm to 100 μm. The fly ash of interest is one in which at least about 80% by weight are particles less than 45 microns.

  Of interest in certain embodiments of the present invention is the use of highly alkaline fluidized bed combustor (FBC) fly ash.

  Also of interest in embodiments of the present invention is the use of bottom ash. Bottom ash is formed as agglomerates from coal combustion in coal fired boilers. The agglomerates have a size such that 90% of the agglomerates fall within a particle size in the range of 0.1 mm to 20 mm, and the bottom ash agglomerates are of the agglomerate size within this range. Wide distribution. The combustion boiler may be a wet bottom boiler or a dry bottom boiler. If it occurs in a wet bottom boiler, the bottom ash is cooled with water to produce boiler slag. The main chemical components of bottom ash are silica and alumina, and in lesser amounts contain oxides of Fe, Ca, Mg, Mn, Na and K, as well as sulfur and carbon.

  In certain embodiments, more interesting is the use of volcanic ash as ash. Volcanic ash is made up of small tephras (ie, a large number of finely divided rocks and glass formed by volcanic eruptions) less than 2 millimeters (0.079 inches) in diameter.

  Cement kiln dust is also useful as a waste source of metal oxides, for example providing CaO and MgO, which can be used both as a divalent cation source and as a proton remover source. .

  A fine by-product of cement production, which is collected by a dust collection system (for example, a cyclone, an electric dust collector, a bughouse, etc.), and classified into four types of cement kiln dust. It can be one of the categories, each of which is suitable as a metal oxide waste source for the present invention. The four categories are based on two different cement kiln processes and two different dust collection processes. Taking this into account, a wet kiln process that receives the feed material in the form of a slurry, and a cement kiln dust from a dry process kiln process that dries the feed material and receives it in the form of a slurry are provided in the present invention. Suitable for use. In each type of kiln, dust can be collected in two ways: some of the dust may be separated and returned to the kiln from the dust collection system closest to the kiln (eg, a cyclone). Alternatively, the entire amount of dust produced may be recycled or discarded. Cement kiln dust obtained from any type of collection system is suitable for use in the present invention.

  The chemical and physical properties of cement kiln dust are highly dependent on the dust collection method employed in the cement manufacturing facility. Chemically, cement kiln dust has a composition similar to normal Portland cement. The main components of cement kiln dust are lime, iron, silica, and alumina compounds. The concentration of free lime in cement kiln dust is highest with coarse particles collected closest to the kiln. Thus, coarse particles with a high concentration of free lime are particularly suitable for the method and system of the present invention. However, the finer particles of cement kiln dust tend to exhibit higher concentrations of sulfate and / or alkali, and the finer particles also contain, for example, CaO in useful concentrations, so that this invention also has Is suitable. In a system where the coarser particles of cement kiln dust are returned to the kiln without being separated, the total free dust will be high in all dust (the reason is that some coarse particles are Because it contains). The cement kiln dust may be used as a metal oxide waste source that provides divalent cations and proton scavengers. Table 2 (Collins, R.J. and J.J. 1983) lists typical compositions for fresh and stockpile cement kiln dust, but as can be seen, some of the cement kiln dust that has been stockpile and has been exposed to the atmosphere for extended periods of time. The content of free lime or free magnesia, if any, is very low. Accordingly, fresh cement kiln dust is preferred over stored cement kiln dust that has been exposed to ambient air for a significantly longer period of time.

  For example, slag may be employed as a proton removing agent (and further a source of divalent cations) for raising the pH of the precipitation reaction mixture charged with CO2. The slag may be used as a single proton scavenger, or one or more additional proton scavengers (eg, other metal oxide waste sources, as described above, auxiliary It may be used in combination with a proton removing agent. Similarly, the slag may be a source of a single divalent cation, or an additional source of one or more divalent cations (eg, other metal oxides as described above). Waste sources, supplemental sources of divalent cations, etc.) may be used in combination. Slag is generated during processing of metal ore (ie, smelting metal ore to refine the metal) and contains calcium and magnesium oxides, as well as compounds of iron, silicon, and aluminum . In some embodiments, the use of slag as a source of proton scavengers or divalent cations provides the additional benefit of allowing reactive silicon and alumina to be introduced into the precipitation product. Slags that may be suitable in the present invention include, but are not limited to: smelter slag from iron smelting, slag from steel arc furnace or blast furnace processing, copper slag, nickel slag , And rinse slag.

Additives Additives other than proton scavengers may be added to the precipitation reaction mixture to affect the nature of the resulting precipitated material. Thus, in some embodiments, additives are added to the precipitation reaction mixture prior to or when the precipitation reaction mixture is placed in precipitation conditions. A trace amount of certain additives favors certain calcium carbonate polymorphs. For example, vaterite is a highly unstable polymorph of CaCO3 that precipitates in various polymorphs and rapidly converts to calcite, but this vaterite is added with a trace amount of lanthanum, such as lanthanum chloride. Therefore, it can be obtained with a very high yield. In order to produce a polymorph of calcium carbonate, other transition metals may be added. For example, it is known that when ferrous or ferric iron is added, dolomite (protodolomite) having a messy structure is easily generated.

Methods The method and system of the present invention is a carbonate-containing composition prepared from an aqueous solution containing dissolved carbon dioxide (eg, from an industrial waste stream containing CO 2), a divalent cation (eg, Ca ²⁺ , Mg ²⁺ ) and a proton scavenger (or a method for causing proton scavenging), which are described in more detail below.

  Metal oxide waste sources such as combustion ash (eg, fly ash, bottom ash, boiler slag), cement kiln dust, or slag (eg, iron slag, phosphorus slag) prepare the compositions described herein Can be a single source of divalent metal cations for Thus, in some embodiments, the only source of divalent metal cations is combustion ash selected from fly ash, bottom ash, and boiler slag. In some embodiments, the only source of divalent metal cations is cement kiln dust. In some embodiments, the only source of divalent metal cations is slag (eg, iron slag, phosphorus slag). Metal oxide waste sources such as combustion ash (eg, fly ash, bottom ash, boiler slag), cement kiln dust, or slag (eg, iron slag, phosphorus slag) can also be produced from the compositions described herein. It can be a single source of proton scavenger for preparation. Thus, in some embodiments, the only source of proton scavenger is combustion ash selected from fly ash, bottom ash, and boiler slag. In some embodiments, the sole source of proton scavenger is cement kiln dust. In some embodiments, the only source of proton scavenger is slag (eg, iron slag, phosphorus slag). In some embodiments, metal oxide waste sources such as combustion ash (eg, fly ash, bottom ash, boiler slag), cement kiln dust, or slag (eg, iron slag, phosphorus slag) are fresh water or distilled. By adding to the water, the mineral source content in the water can be increased by enriching the water source with divalent cations, where the fresh or distilled water has a low or zero mineral content. It is. In these embodiments, the metal oxide waste source is not only a divalent cation, but also a source of proton remover.

  In some embodiments, the metal oxide waste source provides a portion of the proton scavenger, such as 10% or less, 20% or less, 40% or less, 60% or less, 80% or less, and the remaining portion. The proton scavenger (or method of causing proton scavenging) is obtained as described herein.

  Using various convenient procedures, the water is contacted with a metal oxide waste source, such as combustion ash (eg, fly ash) or cement kiln dust, to the desired pH (by means of addition of a proton scavenger). ) Or a divalent cation concentration. In some embodiments, flue gas from a coal-fired thermal power plant is passed directly into the precipitation reactor without the use of an electrostatic precipitator or the like and without prior removal of fly ash. In some embodiments, cement kiln dust is placed directly into the precipitation reactor from the cement kiln. In some embodiments, pre-collected fly ash may be placed in a precipitation reactor holding water, where the amount of fly ash added may be adjusted to the desired pH. To increase the level (eg, pH causing precipitation of carbonate-containing precipitation material), eg, pH 7-14, pH 8-14, pH 9-14, pH 10-14, pH 11-14, pH 12-14, or pH 13-14 Adequate amount. The pH of the fly ash-water mixture is preferably about pH 12.2 to 12.4, for example. Similarly, the pH of the cement kiln dust-water mixture should be about pH 12. In some embodiments, the metal oxide waste source is secured to a column or bed. In such embodiments, water is passed into or above a sufficient amount of ash to raise the pH of the water to a desired pH or a specific divalent cation concentration. A fixed metal oxide waste source (eg, fly ash) is used to passivate the fly ash (ie, containment of fly ash, eg, by CaCO 3 (because CaCO 3 is formed under precipitation conditions)) It is useful for relieving. However, in some embodiments, passivating fly ash may be desirable because, for precipitated materials containing passivated fly ash, pozzolanic reactivity (ie, silica and (Or the reaction between aluminosilica and Ca (OH) 2), which opens up additional applications where lower reactivity is desirable. Since both cement kiln dust and combustion ash, such as fly ash, have high base values, they are considered quite basic. By removing the base value and / or divalent cation value, further base value and / or divalent cation value can be obtained from the waste source-water mixture. For example, a waste source-water mixture can be contacted with a CO2 source (which produces carbonic acid in solution) to form a precipitated material that includes calcium carbonate, which, when produced, causes CaO Is further converted to Ca (OH) 2 to form additional divalent cations. Similarly, the waste source-water mixture may be contacted with an aqueous acid such as, but not limited to, HNO3, HCl, and HF. By acid digesting fly ash with acids such as HNO3 and HCl, it is possible to have greater (70% or more) access to CaO and MgO present in fly ash. Acid digestion with aqueous HF allows greater access to CaO and MgO due to reaction with silica and dissolution of the chemical species produced thereby. The amount of CaO and / or MgO leached from fly ash may be increased or decreased by varying the reaction time and acid strength.

  In some embodiments, metal oxide waste sources such as fly ash or cement kiln dust are sublimated (ie, conversion from CaO to Ca (OH) 2 and from MgO to Mg (OH) 2, etc.) You may let them. Any convenient system or method may be used that is effective in reducing combustion ash (eg, fly ash, bottom ash) or cement kiln dust. The elimination of the metal oxide waste source may be achieved by using a slurry retention and paste machine, a paste lime machine, a ball mill lime machine, or a combination or modification of them. The selection of the soaking device depends on the waste source of the metal oxide to be sanitized, the convenience of water, the required space, and the like. For example, a compact paste lime slaker may be advantageous for use in the system and method of the present invention where space is limited and the water supply for squeezing is also limited. It will be. In some embodiments, a ball mill lime slaker is used. Depending on the metal oxide waste source, the soaking efficiency may be affected by the following factors: type of limestone for use in calcination, specific calcination process (eg, temperature history, Type of burner used, post-combustion treatment, scrubber effect, residence time and conditions, etc.), soaking temperature, waste source to water ratio, degree of stirring during soaking, viscosity of slurry, soaking time, and Water temperature (before mixing metal oxide waste source). The type of water can also affect the soaking efficiency. For example, fresh water, which generally has a lower concentration of divalent cations than seawater, may be much more efficient in extracting CaO and MgO from fly ash, but the type of water is generally Will depend on the availability at the location of the precipitation plant. Thus, the method of the present invention also includes modifying those factors for timely summation (ie, timescale summation that can streamline industrial processes). For example, the soaking temperature may be corrected. In some embodiments, the soaking temperature ranges from room temperature (about 70 ° F.) to about 220 ° F. In some embodiments, the soaking temperature is 70-100 ° F, 100-220 ° F, 120-220 ° F, 140-220 ° F, 160-220 ° F, 160-200 ° F, Or 160-185 ° F. If auxiliary heating is required to increase the soaking temperature (beyond that obtained from the exothermic conversion reaction from CaO to Ca (OH) 2), for example from flue gas Waste heat may be used. Similarly, other external heat sources (for example, heated water) may be used. If the metal oxide waste source is highly reactive (ie, fly ash or cement kiln dust containing high concentrations of CaO, for example), the heat should be reduced, for example, It may be used to heat an air stream for use in drying the precipitated material. For example, the soaking pressure may be corrected. In some embodiments, the soothing pressure is from normal atmospheric pressure (about 1 bar) to about 50 bar. In some embodiments, the soaking pressure is 1 to 2.5 bar, 1 to 5 bar, 1 to 10 bar, 10 to 50 bar, 20 to 50 bar, 30 to 50 bar, or 40 to 50. Bar. In some embodiments, soaking is performed under ambient conditions (ie, standard atmospheric temperature and pressure). The ratio of water to waste sources may also be modified. In some embodiments, the ratio of water to metal oxide waste source is from (1: 1) to (1: 1.5), (1: 1.5) to (1: 2), ( 1: 2)-(1: 2.5), (1: 2.5)-(1: 3), (1: 3)-(1: 3.5), (1: 3.5)-( 1: 4), (1: 4) to (1: 4.5), (1: 4.5) to (1: 5), (1: 5) to (1: 6), (1: 6) ~ (1: 8), (1: 8) ~ (1:10), (1:10) ~ (1:25), (1:25) ~ (1:50), or (1:50) ~ (1: 100). The ratio of waste source to water may also be modified. In some embodiments, the ratio of metal oxide waste source to water is from (1: 1) to (1: 1.5), (1: 1.5) to (1: 2), ( 1: 2)-(1: 2.5), (1: 2.5)-(1: 3), (1: 3)-(1: 3.5), (1: 3.5)-( 1: 4), (1: 4) to (1: 4.5), (1: 4.5) to (1: 5), (1: 5) to (1: 6), (1: 6) ~ (1: 8), (1: 8) ~ (1:10), (1:10) ~ (1:25), (1:25) ~ (1:50), or (1:50) ~ (1: 100). In some embodiments, where a metal oxide waste source such as fly ash is fed directly to the precipitation reactor, the ratio of the waste source to water may be very low. In such embodiments, additional waste sources (eg, fly ash) may be added to the precipitation reactor to increase the ratio of waste source to water, or waste source water. The ratio may be reduced to reduce the ratio. The soaking time may also be modified because it affects the soaking efficiency. In some embodiments, the time required to complete hydration (eg, production of Ca (OH) 2 from CaO) is 12-20 hours, 20-30 hours, 30-40 hours. 40 to 60 hours, 60 to 100 hours, 100 to 160, 100 to 180, and 180 to 200 hours. In some embodiments, the relaxation time required to complete hydration is less than 12 hours, 6-12 hours, 3-6 hours, 1-3 hours, or less than 1 hour. In some embodiments, the time required to complete hydration is between 30 minutes and 1 hour. In some embodiments, the relaxation time is between 15-30 minutes, 15-25 minutes, and 15-20 minutes. In some embodiments, the soothing time is between 5-30 minutes, 5-20 minutes, 5-15 minutes, and 5-10 minutes. In some embodiments, the relaxation time is between 1-5 minutes, 1-3 minutes, and 2-3 minutes. Agitation can also affect the soaking efficiency, for example by eliminating hot spots and cold spots. Furthermore, the soaking efficiency may be increased by pretreating the metal oxide waste source. For example, fly ash may be jet milled or ball milled prior to soaking. By changing any one of the above-mentioned relaxation factors, it will also change the further relaxation factors, and each relaxation procedure will vary depending on the materials available. Will be recognized. Therefore, in the present invention, the ratio of converting CaO present in the waste source to Ca (OH) 2 is 10%, 20%, 30%, 40%, 50%, 60% %, 70%, 80%, 90%, 95%, 97%, 98%, 99%, or 99.9%. Similarly, in the present invention, the ratio of converting MgO present in the waste source to Mg (OH) 2 is 10%, 20%, 30%, 40%, 50%, It can be over 60%, over 70%, over 80%, over 90%, over 95%, over 97%, over 98%, over 99%, or over 99.9%. The higher the conversion rate, the higher the efficiency of the process.

  Metal oxide waste sources such as combustion ash, cement kiln dust, or slag (eg, iron slag, phosphorus slag), supplemental divalent cation sources such as combustion ash, cement kiln dust, or slag (eg, , Iron slag, phosphorus slag) may be used in combination. Thus, in some embodiments, the source of divalent cations is a combination of a divalent cation source and combustion ash selected from fly ash, bottom ash, and boiler slag. For example, the divalent cation source may be a combination of fly ash and seawater. When used as a combination (eg, a combination of combustion ash and other sources of divalent cations), the combustion ash may be used in any order. For example, the basic solution may already contain divalent cations (eg, seawater) prior to adding combustion ash, or a source of divalent cations may be added to the fly ash slurry in water. May be. In any of these embodiments, CO2 may be added either before or after the combustion ash, as will be described in more detail below.

  Waste sources such as combustion ash, cement kiln dust, or slag (eg, iron slag, phosphorus slag), supplemental proton remover sources such as combustion ash, cement kiln dust, or slag (eg, iron slag, You may use it in combination with the mixture of a phosphorus slag. Thus, in some embodiments, the source of proton scavenger is a combination of a proton scavenger and a combustion ash selected from fly ash, bottom ash, and boiler slag. Examples of proton scavengers that can be used include: oxides (eg CaO), hydroxides (eg KOH, NaOH, talc (Mg (OH) 2 etc.), carbonates (eg Na2CO3), serpentine, etc. Serpentine, which also releases silica and magnesium into the reaction mixture, ultimately contains carbonate and silica (in addition to those found in combustion ash). The amount of supplemental proton scavenger used depends on the specific nature of the supplemental proton scavenger and the volume of water in which the supplemental proton scavenger is added. An alternative to ancillary proton scavengers is the use of electrochemical methods as previously described to provide proton removal.Electrolysis may be employed. Processes may be used, but such processes include the Castner-Kellner process, and diaphragm cell process, membrane cell process, etc. Hydrolysis product by-products (eg, H2, Sodium metal) may be collected and used for other purposes, such as when a combination of proton scavengers (eg, a combination of combustion ash and other proton scavenger sources) is used. The ash may be used in any order, for example, an additional proton scavenger in a divalent cation-containing solution (eg, seawater) that is already basic prior to addition of the combustion ash or fly ash slurry in water. These may be further basic. In any of these, CO2 may be added either before or after the combustion ash, as will be described in more detail below.

  As explained above, metal oxide waste sources such as combustion ash, cement kiln ash, and slag (eg, iron slag, phosphorus slag), either with or without an auxiliary proton remover, Various combinations may be used. If auxiliary proton removers (and methods that affect proton removal) are used, these auxiliary proton removers may also be used in various suitable combinations. Some embodiments of the present invention provide the following combinations: Use of a combination of an artificial waste (eg, red mud or brown mud from bauxite processing) and a commercially available base (eg, NaOH) A combination of man-made waste with electrochemical methods (ie, deprotonation of carbonic acid, bicarbonate, hydronium, etc.) and naturally-occurring proton scavengers (eg, serpentine minerals); Combine waste with commercially available bases and naturally-occurring proton scavengers, then transfer to serpentine minerals combined with electrochemical methods. The proportion of the various methods that affect proton removal may be adjusted according to conditions and availability, for example, the first five years of the lifetime of the precipitation plant, the anthropogenic waste is converted to commercial bases and Used in combination with naturally-occurring proton scavengers, then may move to a combination of serpentine minerals and electrochemical methods to remove protons (these are more readily available) From).

  In some embodiments, in combination with a proton scavenger (and a method that affects proton scavenging), 1-30% of the proton scavenger is supplied from fly ash, and 20-80% of the proton scavenger is Sourced from waste (eg, red mud), minerals such as serpentine, or combinations thereof, 10-50% of proton removal is provided by electrochemical methods. For example, in some embodiments, providing a combination of a proton remover and an electrochemical method, 10% of the proton remover is supplied from fly ash and 60% of the proton remover is taken from a mining process (eg, , Red mud), and 30% of proton removal will be covered by electrochemical methods. In some embodiments, providing a combination of proton scavenger and electrochemical method, 10% of the proton scavenger is supplied from fly ash and 60% of the proton scavenger is from a naturally occurring mineral supply Sourced from waste from a source (eg, dissolved serpentine), 30% of proton removal is provided by an electrochemical method. In some embodiments, a combination of a proton scavenger and an electrochemical method is provided, in which case 30% of the proton scavenger is in the first 5 years of the lifetime of the precipitation plant, Sourced from fly ash, 70% of the proton remover is provided from waste from the mining process (eg, red mud), and from the beginning of its sixth year, 10% of the proton remover Sourced from ash, 60% of the proton scavenger is the result of dissolving a naturally occurring mineral source (eg, serpentine) so that 30% of the proton scavenging is covered by electrochemical methods.

An aqueous solution containing a divalent cation (eg, an alkaline earth metal cation, eg, Ca ²⁺ and Mg ²⁺ ), and a divalent cation-containing solution of the one or more substances based on the precipitation conditions (ie, for example, based on pH) It may be brought into contact with the CO2 supply source at any timing before, during, or after being subjected to conditions that cause precipitation. Thus, in some embodiments, in order to favor the formation of carbonate and / or bicarbonate compounds, an aqueous solution of divalent cations and a source of CO2 can be used prior to subjecting the aqueous solution to precipitation conditions. Make contact. In some embodiments, in order to favor the formation of carbonate and / or bicarbonate compounds, an aqueous solution of a divalent cation is used as a source of CO2 while the aqueous solution is in precipitation conditions. Make contact. In some embodiments, in order to favor the formation of carbonate and / or bicarbonate compounds, the aqueous solution of the divalent cation is CO2 prior to and during placement of the aqueous solution in precipitation conditions. Contact with the source of In some embodiments, in order to favor the formation of carbonate and / or bicarbonate compounds, the aqueous solution of divalent cations is contacted with a source of CO2 after the aqueous solution has been subjected to precipitation conditions. In some embodiments, an aqueous solution of a divalent cation is added to the CO2 source before, during, and after the aqueous solution is subjected to precipitation conditions to favor the formation of carbonate and / or bicarbonate compounds. Contact with. In some embodiments, the divalent cation-containing aqueous solution may be cycled more than once, in which case, in the first cycle of precipitation, the calcium carbonate and magnesium carbonate minerals are primarily removed to make the alkaline The solution remains, but additional divalent cations may be added thereto. Contacting carbon dioxide with a recycled solution of divalent cations allows more carbonate and / or bicarbonate compounds to precipitate. It will be appreciated that in these embodiments, the aqueous solution after the first precipitation cycle may be contacted with a CO2 source before, during and / or after the divalent cation is added. I will. In some embodiments, an aqueous solution that is free of divalent cations or has a low concentration of divalent cations is contacted with CO2. In these embodiments, the water may be recycled or newly introduced. Therefore, the order of addition of the CO2 and metal oxide waste sources may be varied. For example, a metal oxide waste source such as fly ash, cement kiln dust, or slag, each of which provides a divalent cation, proton scavenger, or both, is added to, for example, brine, sea water, or fresh water, Thereafter, CO2 may be added. In another example, CO2 may be added to, for example, brine, seawater, or fresh water, followed by addition of fly ash, cement kiln dust, or slag.

  The divalent cation-containing aqueous solution may be contacted with the CO2 source using various convenient procedures. When the CO2 is a gas, the contact procedures of interest include (but are not limited to) the following: direct contact procedures (eg, bubbling CO2 gas into an aqueous solution) Co-current contact means (ie, contact between a gas phase flow and a liquid phase flow flowing in one direction), countercurrent means (ie, a gas phase flow and a liquid phase flow flowing in opposite directions) Between contact) etc. Thus, contacting may be performed using an infuser, bubbler, fluid venturi reactor, sparger, gas filter, spray, tray, packed column reactor, etc., as convenient. In some embodiments, a flat jet nozzle is used to form a liquid sheet of solution, and the CO2 gas and its liquid film are directed in countercurrent, cocurrent, or crossflow directions, or any other suitable Gas-liquid contact is carried out by moving in a simple manner. See, for example, U.S. Patent Application No. 61 / 158,992, filed on March 10, 2009, which is hereby incorporated by reference in its entirety. . In some embodiments, gas-liquid contact is performed by contacting droplets of a solution having an average diameter of 500 micrometers or less, such as 100 micrometers or less, with a CO2 gas source. In some embodiments, a catalyst is used to accelerate the dissolution of carbon dioxide into the solution to accelerate the reaction toward equilibrium, but the catalyst may be an inorganic substance such as zinc dichloride. Or it may be cadmium, or an organic substance such as an enzyme (eg, carbon dehydrase).

  In the process of the present invention, a volume of CO2 charged water produced as described above is used to separate the carbonate-containing precipitation material and the supernatant (ie, the portion of the precipitation reaction mixture left behind after the precipitation material has precipitated). ) Under sufficient precipitation conditions for carbonate compounds. Various convenient precipitation conditions may be employed, which result in the formation of carbonate-containing precipitation material from the CO 2 -charged precipitation reaction mixture. Precipitation conditions include conditions that adjust the physical environment of the precipitation reaction mixture charged with CO2 to produce the desired precipitation material. For example, the temperature of the precipitation reaction mixture charged with CO2 may be raised to a point that is suitable for precipitating the desired carbonate-containing precipitation material. In such embodiments, the temperature of the precipitation reaction mixture charged with CO2 may be raised to a value between 5 ° C and 70 ° C, such as between 20 ° C and 50 ° C, such as between 25 ° C and 45 ° C. The predetermined series of precipitation conditions may include a temperature in the range of 0 ° C. to 100 ° C., and in certain embodiments, the temperature may be increased to produce the desired precipitation material. . In certain embodiments, sources with low or zero carbon dioxide emissions (e.g., solar energy sources, wind energy sources, hydropower energy sources, waste heat from flue gas from carbon emission devices, etc.) ) To raise the temperature of the precipitation reaction mixture. In some embodiments, heat from the flue gas from the combustion of coal or other fuel may be utilized to raise the temperature of the precipitation reaction mixture. The pH of the precipitation reaction mixture charged with CO2 may be raised to a pH suitable for precipitating the desired carbonate-containing precipitation material. In such an embodiment, the pH of the CO2 charged precipitation reaction mixture is raised to an alkaline level for precipitation, but preferably the carbonate is bicarbonate. The pH may be raised to pH 9 or higher, such as pH 10 or higher, such as pH 11 or higher. For example, when fly ash is used to raise the pH of the precipitation reaction mixture or the precursor of the precipitation reaction mixture, the pH may be about 12.5 or higher.

  Thus, a series of precipitation conditions to produce the desired precipitation material from the precipitation reaction mixture includes the temperature and pH, and possibly the concentration of additives and ionic species in water, as described above. It is. The precipitation conditions may further include factors such as: mixing speed, form of stirring (eg, ultrasound), and presence of seed crystals, catalyst, membrane, or substrate. In some embodiments, precipitation conditions include supersaturation conditions, temperature, pH, and / or concentration gradients, or various repetitions or changes of these parameters. Procedures employed to prepare carbonate-containing precipitated material in the present invention (from the decontamination of the starting point, for example fly ash, to the end point, for example, drying of the precipitated material or shaping of the precipitated material into aggregate) May be batch, semi-batch, or continuous procedures. It will be appreciated that in a continuous flow system, the precipitation conditions for producing a given precipitation material may be different as compared to a semi-batch or batch system.

  After the carbonate-containing precipitation material is produced from the precipitation reaction mixture, it is separated from the reaction mixture to become separated precipitate material (eg, wet cake) and supernatant, as seen in FIG. The precipitated material may be stored in the supernatant for some time and then precipitated and separated (eg, by drying). For example, the precipitated material may be stored in the supernatant at a temperature ranging from 1 ° C to 40 ° C, such as from 20 ° C to 25 ° C for a period ranging from 1 to 1000 days, such as from 1 to 10 days. Separation of the precipitated material from the precipitation reaction mixture is carried out using any of a number of convenient approaches, including the following: draining methods (eg, gravity precipitation of the precipitated material) Settling and draining), decanting method, filtration method (for example, gravity filtration method, vacuum filtration method, filtration method using forced air), centrifugal separation method, pressurization method, or various combinations thereof. Separating bulk water from the precipitated material produces a wet cake of the precipitated material, or a dehydrated precipitated material. As described in detail in U.S. Patent Application No. 61/170086, filed April 16, 2109, incorporated herein by reference, liquid-solid separators such as , One of the Epuramat Extreme-Separator (“ExSep”) liquid-solid separators, the Xerox PARC spiral concentrators, or the Epuramat ExSep or Xerox PARC spiral concentrators can be used to remove the precipitated material from the precipitation reaction mixture. Useful for separation.

  In some embodiments, the dehydrated precipitated material thus obtained is then dried to produce a product (eg, cement, pozzolanic cement, aggregate, or non-reactive, storage-stable CO 2 sequestering). (CO2-sequestering product). Drying may be performed by aeration drying the precipitated material. When the precipitated material is air-dried, the air-drying is preferably performed at a temperature in the range of -70 ° C to 120 ° C. In certain embodiments, drying is performed by freeze-drying, ie, lyophilization, in which the precipitated material is frozen, the ambient pressure is reduced, and the frozen water in the precipitated material is directly Apply enough heat to sublimate as a gas. In yet another embodiment, the precipitated material is spray dried to dry the precipitated material, wherein the precipitated material is included in a hot gas (eg, a gaseous waste stream from a power plant). The liquid is dried by feeding it, the liquid feed is pumped through the atomizer through the main drying chamber, and the hot gas is passed in parallel or countercurrent with the direction of the atomizer. Depending on the particular drying procedure of the system, the drying station (detailed below) may include filtering elements, freeze drying structures, spray drying structures, and the like. In certain embodiments, if appropriate, the drying process may be performed using waste heat from a power plant or similar facility. For example, in some embodiments, aggregates are manufactured using high temperatures (eg, waste heat from power plants), pressure, or combinations thereof.

  After separating the precipitated material from the supernatant, the separated precipitated material may be further processed if desired, but the precipitated material can be stored for a long period of time and simply transferred to a location for sequestering CO2. May be. For example, the carbonate-containing precipitated material may be transported and stored on a long-term storage site, for example, above the ground (as a storage-stable CO2 sequestering material), underground, deep sea, and the like.

  The supernatant resulting from the precipitation process, or a slurry of the precipitated material, may be processed as desired. For example, the supernatant or slurry may be returned to the source of the divalent cation-containing aqueous solution (eg, the ocean) or elsewhere. In some embodiments, the supernatant may be contacted with a source of CO2 to sequester additional CO2, as explained above. For example, in embodiments where the supernatant is returned to the ocean, the supernatant may be contacted with a gaseous CO2 waste source in a manner sufficient to increase the concentration of carbonate present in the supernatant. As explained above, the contacting may be performed using any convenient procedure. In some embodiments, the supernatant has an alkaline pH and contact with the CO2 source is adjusted to a pH of pH 5-9, pH 6-8.5, or pH 7.5-8.2. The method is carried out in such a way as to fall within the range.

  The method of the present invention may be carried out at the following locations: on the ground (eg, where a suitable divalent cation-containing source is present or where it can be easily and inexpensively carried), at sea, An assembly in the ocean or other divalent cations (the assembly may be naturally derived or artificial). In some embodiments, systems are employed to implement the methods described above, such systems include those described in more detail below.

  In some embodiments of the present invention, fly ash is used as the sole or major source of divalent cations and / or as a proton scavenger for precipitating carbonate-containing precipitation materials. In such an embodiment, water (eg, fresh water, sea water, brine) may be used to subdue the fly ash to produce a decontaminated fly ash mixture, but the decontaminated fly ash The pH of the mixture may be pH 7-14, pH 8-14, pH 9-14, pH 10-14, pH 11-14, pH 12-14, or pH 13-14. In such a hydrated fly ash mixture, the fly ash concentration in the water is 1-10 g / L, 10-20 g / L, 20-30 g / L, 30-40 g / L, 40-80 g / L. L, 80-160 g / L, 160-320 g / L, 320-640 g / L, or 640-1280 g / L, and the soaking temperature is from room temperature (about 70 ° F.) to about 220 ° F, 70-100 ° F, 100-220 ° F, 120-220 ° F, 140-220 ° F, 160-220 ° F, 160-200 ° F, or 160-185 ° F. . To optimize extraction and conversion of CaO to Ca (OH) 2, high shear mixing, wet milling, and / or sonication are used to break open ash pores Thus, it is better to reach the trapped CaO. High shear mixing, wet milling, and / or sonication, in addition to providing access to CaO confined in fly ash matrix (eg, SiO 2 matrix), cement, Improve the strength of pozzolanic cement and related end products. After high shear mixing and / or wet milling, the liquefied fly ash mixture can be converted into a source of carbon dioxide (eg with or without dilution of the fly ash mixture), eg coal-fired thermal power plant Contact with flue gas from or exhaust gas from cement kiln. Any of the many gas-liquid contact procedures described above may be utilized. Gas-liquid contact is continued until the pH of the precipitation reaction mixture is constant, after which the precipitation reaction mixture is allowed to stir overnight. The rate of lowering the pH may be adjusted by adding auxiliary fly ash during gas-liquid contact. Further, after aeration, supplemental fly ash may be added to raise the pH to a basic level for precipitating some or all of the precipitated material. In either case, the precipitated material can be generated by removing protons from certain species (eg, carbonate, bicarbonate, hydronium) in the precipitation reaction mixture. The precipitated material containing the carbonate and siliceous compound can then be separated and optionally further processed.

  As noted above, in some embodiments of the present invention, fly ash is used as the sole or main source of divalent cations and / or as a proton scavenger for precipitating carbonate-containing precipitation materials. To do. In such an embodiment, water (eg, fresh water, sea water, brine) may be used to subdue the fly ash to produce a decontaminated fly ash mixture, but the decontaminated fly ash The pH of the mixture may be pH 7-14, pH 8-14, pH 9-14, pH 10-14, pH 11-14, pH 12-14, or pH 13-14. In such a hydrated fly ash mixture, the fly ash concentration in the water is 1-10 g / L, 10-20 g / L, 20-30 g / L, 30-40 g / L, 40-80 g / L. L, 80-160 g / L, 160-320 g / L, 320-640 g / L, or 640-1280 g / L, and the soaking temperature is from room temperature (about 70 ° F.) to about 220 ° F, 70-100 ° F, 100-220 ° F, 120-220 ° F, 140-220 ° F, 160-220 ° F, 160-200 ° F, or 160-185 ° F. . As described above, extraction and conversion of CaO to Ca (OH) 2 can be optimized using high shear mixing and / or wet milling. However, after any additional processing, the fly ash is separated from the tempered fly ash mixture, dried and usable as pozzolans (see below), and contains divalent cations and carbonates. A supernatant containing a proton scavenger for precipitating the precipitated material may be produced. The supernatant may then be contacted (with or without dilution of the fly ash mixture) with a source of carbon dioxide such as flue gas from a coal-fired power plant or exhaust gas from a cement kiln. . Gas-liquid contact is continued until the pH is constant, after which the precipitation reaction mixture is allowed to stir overnight. The rate at which the pH decreases may be adjusted by adding auxiliary fly ash during gas-liquid contact. In addition, after gas-liquid contact, supplemental fly ash may be added to raise the pH back to a basic level for precipitating some or all of the precipitated material. In either case, the precipitated material can be generated by removing protons from certain species (eg, carbonate, bicarbonate, hydronium) in the precipitation reaction mixture. The precipitated material containing carbonate may then be separated and optionally further processed. For example, carbonate-containing precipitated material with little or no siliceous material may be dried and used in the final product. The carbonate-containing precipitated material is better combined with the separated fly ash sludge, in which case the precipitated material and fly ash sludge are wet mixed, dried, or a combination of both. To produce a siliceous composition containing carbonate. Such materials can have pozzolanic properties derived from the addition of wet (ie, fly ash sludge) or dry (ie, dry fly ash sludge) fly ash-based pozzolans.

  In some embodiments of the present invention, fly ash is used in combination with a source of divalent cations and / or a proton scavenger for precipitating carbonate-containing precipitation material. In such embodiments, water (eg, fresh water, sea water, brine) may be used to dehydrate the fly ash to produce a dehydrated fly ash mixture. A supplemental proton scavenger may then be added to the hydrated fly ash mixture to produce a high pH hydrated fly ash mixture, in which case the high pH hydrated mixture. The pH of the fly ash mixture should be pH 7-14, pH 8-14, pH 9-14, pH 10-14, pH 11-14, pH 12-14, or pH 13-14, and the fly ash is completely dissolved Alternatively, it may be dissolved at some degree. For example, 75% fly ash may be dissolved by adding an auxiliary proton scavenger. In such a hydrated fly ash mixture, the fly ash concentration in the water is 1-10 g / L, 10-20 g / L, 20-30 g / L, 30-40 g / L, 40-80 g / L. L, 80-160 g / L, 160-320 g / L, 320-640 g / L, or 640-1280 g / L, and the soaking temperature is from room temperature (about 70 ° F.) to about 220 ° F, 70-100 ° F, 100-220 ° F, 120-220 ° F, 140-220 ° F, 160-220 ° F, 160-200 ° F, or 160-185 ° F. . In order to facilitate dissolution of various undissolved fly ash, the fly ash cavities may be broken using high shear mixing and / or wet milling to obtain smaller fly ash particles. . After high shear mixing and / or wet milling, the liquefied fly ash mixture can be converted into a source of carbon dioxide (eg with or without dilution of the fly ash mixture), eg coal-fired thermal power plants From flue gas from or from exhaust gas from a cement kiln. Any of the many gas-liquid contact procedures described above may be utilized. Gas-liquid contact may be continued until the pH is constant, after which the precipitation reaction mixture may be allowed to stir overnight. The rate at which the pH decreases may be adjusted by adding auxiliary fly ash or other auxiliary proton scavenger during the gas-liquid contact. In addition, after gas-liquid contact, supplemental fly ash may be added to raise the pH back to a basic level for precipitating some or all of the precipitated material. In either case, the precipitated material can be generated by removing protons from certain species (eg, carbonate, bicarbonate, hydronium) in the precipitation reaction mixture. The precipitated material containing the carbonate and siliceous compound can then be separated and optionally further processed.

Accordingly, provided is contacting an aqueous solution with a source of metal oxide from an industrial process; charging the aqueous solution with carbon dioxide from a source of carbon dioxide from an industrial process; and Subjecting to precipitation conditions under atmospheric pressure to produce a carbonate-containing precipitation material. In some embodiments, the metal oxide source and the carbon dioxide source are from the same industrial process. In some embodiments, contacting the aqueous solution with a source of metal oxide is performed prior to charging the aqueous solution with a source of carbon dioxide. In some embodiments, contacting the aqueous solution with a source of metal oxide is performed simultaneously with charging the aqueous solution with a source of carbon dioxide. In some embodiments, contacting the aqueous solution with a source of metal oxide, charging the aqueous solution with a source of carbon dioxide, and subjecting the aqueous solution to precipitation conditions are performed simultaneously. . In some embodiments, the metal oxide source and the carbon dioxide source are supplied from the same waste stream. In some embodiments, the waste stream is flue gas from a coal-fired power plant. In some embodiments, the coal-fired power plant is a lignite-fired power plant. In some embodiments, the waste stream is kiln emissions from a cement plant. In some embodiments, the metal oxide source is fly ash. In some embodiments, the metal oxide source is cement kiln dust. In some embodiments, the waste stream further includes SOx, NOx, mercury, or various combinations thereof. In some embodiments, the source of metal oxide further provides a divalent cation for generating a precipitated material. In some embodiments, both the metal oxide source and the aqueous solution include a divalent cation to produce a precipitated material. In some embodiments, the metal oxide source is fly ash or cement kiln dust. In some embodiments, the aqueous solution comprises brine, seawater, or fresh water. In some embodiments, the divalent cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof. In some embodiments, the source of metal oxide provides a proton scavenger to produce a precipitated material. In some embodiments, the metal oxide source hydrates CaO, MgO, or a combination thereof in the aqueous solution to provide a proton scavenger. In some embodiments, the source of metal oxide further provides silica. In some embodiments, the source of metal oxide further provides alumina. In some embodiments, the source of metal oxide further provides ferric oxide. In some embodiments, red mud or brown mud from bauxite processing also provides a proton scavenger. In some embodiments, electrochemical methods that affect proton removal further provide for the formation of precipitated material.

  In some embodiments, the method further includes separating the precipitated material from the aqueous solution in which the precipitated material is produced. In some embodiments, the precipitated material comprises CaCO3. In some embodiments, CaCO3 comprises calcite, aragonite, vaterite, or combinations thereof. In some embodiments, the precipitation material further comprises MgCO3. In some embodiments, the CaCO3 includes halo stones and the MgCO3 includes neskehonite. In some embodiments, the method includes processing the precipitated material to form a building material. In some embodiments, the building material is hydraulic cement. In some embodiments, the building material is pozzolanic cement. In some embodiments, the building material is aggregate.

Further provided is the step of contacting the aqueous solution with a waste stream comprising carbon dioxide and a source comprising a metal oxide, and subjecting the aqueous solution to precipitation conditions to produce a carbonate-containing precipitated material. Is the method. In some embodiments, the waste stream is flue gas from a coal-fired power plant. In some embodiments, the coal-fired power plant is a lignite-fired power plant. In some embodiments, the metal oxide source is fly ash. In some embodiments, the waste stream is kiln emissions from a cement plant. In some embodiments, the metal oxide source is cement kiln dust. In some embodiments, the waste stream further includes SOx, NOx, mercury, or various combinations thereof. In some embodiments, the divalent cation for generating the precipitated material is provided by a source of metal oxide, an aqueous solution, or a combination thereof. In some embodiments, the aqueous solution comprises brine, seawater, or fresh water. In some embodiments, the divalent cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof. In some embodiments, the source of metal oxide further provides a proton scavenger for generating a precipitated material. In some embodiments, the source of metal oxide hydrates CaO, MgO, or a combination thereof in the aqueous solution to provide a proton scavenger. In some embodiments, the source of metal oxide further provides silica. In some embodiments, the source of metal oxide further provides alumina. In some embodiments, the source of metal oxide further provides ferric oxide. In some embodiments, red mud or brown mud from bauxite processing also provides a proton scavenger. In some embodiments, electrochemical methods that affect proton removal further provide for the formation of precipitated material. In some embodiments, the precipitated material comprises CaCO3. In some embodiments, CaCO3 comprises calcite, aragonite, vaterite, or combinations thereof. In some embodiments, the method further includes separating the precipitated material from the aqueous solution in which the precipitated material is produced. In some embodiments, the method includes processing the precipitated material to form a building material. In some embodiments, the building material is hydraulic cement. In some embodiments, the building material is pozzolanic cement. In some embodiments, the building material is aggregate.

Compositions and Other Products The present invention provides methods and systems for producing carbonate-containing compositions from CO2 utilizing a metal oxide waste source, wherein the CO2 is broadly It may come from various sources, such as industrial waste by-products, for example gaseous waste streams generated by burning carbon-based fuels at power plants. Accordingly, the present invention provides a method for removing or separating CO2 from a gaseous waste source of CO2, and non-gaseous, storage-stable forms of CO2 (eg, structures such as buildings and infrastructure). It is provided with a method for securing the CO2 to the atmosphere so that the CO2 is not released into the atmosphere. Furthermore, the present invention also provides an effective method for sequestering CO2 and for long-term storage of CO2 in a usable product.

  Precipitating material in storage stable form (which may be simply dried precipitating material) is for example 1 year or more, 5 years or more, 10 years or more, 25 years or more, 50 years or more , Over 100 years, over 250 years, over 1000 years, over 10,000 years, over 1,000,000 years, or even over 100,000,000 years or longer Without waking up, it may be stored on the ground under exposed (ie, open to the atmosphere) conditions. The storage-stable form of the precipitated material decomposes only slightly (if any) during storage on the ground under normal rainwater pH conditions, so that the CO2 released from the product. The amount of degradation (if any) measured as gas will not exceed 5% / year and in certain embodiments will not exceed 1% / year. The ground storage-stable form of the precipitated material is stable under a variety of different environmental conditions, such as temperatures in the range of -100 ° C to 600 ° C and humidity in the range of 0 to 100%. The condition may be fine weather, strong wind, or storm. In some embodiments, the precipitated material produced by the method of the present invention is employed as a building material (eg, various types of man-made structures such as building materials for buildings, roads, bridges, dams, etc.). , Effectively contain CO2 in the constructed environment. Various man-made structures such as foundations, parking structures, houses, office buildings, commercial offices, government buildings, infrastructures (eg pavements; roads; bridges; overpasses; walls; foundations for gates, fences and poles) ;) Is considered part of the architectural environment. The mortar of the present invention has been found to be used for joining building material blocks (for example, bricks) and filling gaps between building material blocks. Mortars can also be used to fix existing structures (e.g., replace parts where the original mortar is damaged or brittle), among other applications.

  In certain embodiments, the carbonate-containing composition is employed as a component of hydraulic cement, which sets and hardens after being combined with water. The setting and hardening of the product obtained by combining the precipitated material with cement and water results in a hydrate formed by the reaction of the cement and water, where the hydrate is true for water. Does not dissolve above. Hydrocement of such carbonate compounds, methods for making the same and use thereof are described in US patent application Ser. No. 12 / 126,776 (Title: “Hydraulic Components Comprising Carbonates Compounds Composition”, application. (May 23, 2008) (the disclosure of this application is incorporated herein by reference).

By adjusting the ratio of the main ions during precipitation, the nature of the precipitated material can be changed. The ratio of the main ions has a considerable influence on the formation of polymorphs. For example, when the magnesium: calcium ratio in water is increased, the polymorph of calcium carbonate in the precipitated material becomes the main component of aragonite rather than low magnesium calcite. When the magnesium: calcium ratio is low, low magnesium calcite is the predominant polymorph. In some embodiments, if both Ca ²⁺ and Mg ²⁺ are present, the ratio of Ca ²⁺ to Mg ²⁺ in the precipitated material (ie, Ca ²⁺ : Mg ²⁺ ) is (1: 1) to (1: 2.5), (1: 2.5) to (1: 5), (1: 5) to (1:10), (1:10) to (1:25), ( 1:25) to (1:50), (1:50) to (1: 100), (1: 100) to (1: 150), (1: 150) to (1: 200), (1: 200) to (1: 250), (1: 250) to (1: 500), or (1: 500) to (1: 1000). In some embodiments, the ratio of Mg ²⁺ to Ca ²⁺ in the precipitated material (ie, Mg ²⁺ : Ca ²⁺ ) is from (1: 1) to (1: 2.5), (1: 2.5). ) To (1: 5), (1: 5) to (1:10), (1:10) to (1:25), (1:25) to (1:50), (1:50) to (1: 100), (1: 100) to (1: 150), (1: 150) to (1: 200), (1: 200) to (1: 250), (1: 250) to (1 : 500), or (1: 500) to (1: 1000).

  The precipitation rate also has a significant effect on the formation of the compound phase, but the fastest precipitation rate is achieved by seeding the solution containing the desired phase. Without seeding, rapid precipitation can be achieved by rapidly raising the pH of the precipitation reaction mixture, in which case more amorphous components are obtained. The faster the reaction rate, the more silica is incorporated into the carbonate-containing precipitation material if silica is present in the precipitation reaction mixture. Furthermore, the higher the pH, the more rapid the precipitation and the more amorphous precipitation material is produced.

  In addition to the magnesium-containing and calcium-containing products of the precipitation reaction, compounds and materials including silicon, aluminum, iron, and others may be prepared using the methods and systems of the present invention. Precipitation of such compounds is desirable to alter the reactivity of cements containing the precipitated material obtained from the process and to change the properties of cement and concrete hardeneds produced therefrom. In some embodiments, combustion ash, such as fly ash, is added to the precipitation reaction mixture as one source of those components to add one or more components, such as amorphous silica, amorphous aluminosilicate, etc. Producing a carbonate-containing precipitation material, including crystalline silica, calcium silicate, calcium aluminate silicate, and the like. In some embodiments, the precipitation material comprises carbonate (eg, calcium carbonate, magnesium carbonate) and silica in the following ratios of carbonate: silica: (1: 1) to (1: 1. 5), (1: 1.5) to (1: 2), (1: 2) to (1: 2.5), (1: 2.5) to (1: 3), (1: 3) -(1: 3.5), (1: 3.5)-(1: 4), (1: 4)-(1: 4.5), (1: 4.5)-(1: 5) , (1: 5) to (1: 7.5), (1: 7.5) to (1:10), (1:10) to (1:15), or (1:15) to (1 : 20). In some embodiments, the precipitated material comprises silica and carbonate (eg, calcium carbonate, magnesium carbonate) in the following ratios of silica: carbonate: (1: 1) to (1: 1.5). ), (1: 1.5) to (1: 2), (1: 2) to (1: 2.5), (1: 2.5) to (1: 3), (1: 3) to (1: 3.5), (1: 3.5) to (1: 4), (1: 4) to (1: 4.5), (1: 4.5) to (1: 5), (1: 5) to (1: 7.5), (1: 7.5) to (1:10), (1:10) to (1:15), or (1:15) to (1: 20).

  Precipitated materials including silica and aluminosilicates can be readily employed as pozzolanic cements in the cement and concrete industry due to the presence of fine siliceous and / or aluminosilicic materials. Siliceous and / or aluminosilicic precipitates may be used with Portland cement to produce blended cements or as a direct mineral mixture into the concrete mixture. In some embodiments, the pozzolanic material, which may be precipitated material alone or mixed with additional fly ash and / or wet or dry fly ash sludge, includes calcium and magnesium. In the proportions (above) that perfect the setting time, stiffening and long-term stability of the resulting hydrated product. The interaction with Portland cement may be improved by adjusting the crystallinity of the carbonate, the concentration of chloride, alkali, etc. in the precipitated material. In some embodiments, the siliceous precipitation material comprises silica, wherein 10-20%, 20-30%, 30-40%, 40-50%, 50-60% of the silica, 60-70%, 70-80%, 80-90%, 90-95%, 95-98%, 98-99%, 99-99.9% particles (eg, in the largest dimension) less than 45 microns Have a size. In some embodiments, the siliceous precipitation material comprises aluminosilica, wherein 10-20%, 20-30%, 30-40%, 40-50%, 50-60 of the aluminosilica. %, 60-70%, 70-80%, 80-90%, 90-95%, 95-98%, 98-99%, 99-99.9% have a particle size of less than 45 microns. In some embodiments, the siliceous precipitation material comprises a mixture of silica and aluminosilica, wherein 10-20%, 20-30%, 30-40%, 40-50% of the mixture. 50-60%, 60-70%, 70-80%, 80-90%, 90-95%, 95-98%, 98-99%, 99-99.9% (e.g. ) Having a particle size of less than 45 microns.

  Accordingly, provided is a siliceous composition comprising synthetic calcium carbonate, wherein the calcium carbonate is present in at least two forms selected from calcite, aragonite, and vaterite. In some embodiments, the at least two forms of calcium carbonate are calcite and aragonite. In some embodiments, calcite and aragonite are present in a ratio of 20: 1. In some embodiments, the calcium carbonate and silica are present in a ratio of at least 1: 2 carbonate to silica. In some embodiments, 75% of the silica is amorphous silica with a particle size of less than 45 microns. In some embodiments, the silica particles are wholly or partially encapsulated by synthetic calcium carbonate or synthetic magnesium carbonate.

  Further provided is a siliceous composition comprising synthetic calcium carbonate and synthetic magnesium carbonate, wherein the calcium carbonate is present in at least one form selected from calcite, aragonite, and vaterite, Here, the magnesium carbonate is present in at least one form selected from neskehonite, magnesite, and hydromagnesite. In some embodiments, the calcium carbonate is present as olivine and the magnesium carbonate is present as neskehonite. In some embodiments, the silica comprises no more than 20% siliceous composition. In some embodiments, the silica comprises 10% or less siliceous composition. In some embodiments, the silica particles are wholly or partially encapsulated by synthetic calcium carbonate or synthetic magnesium carbonate.

  In some embodiments, aggregate is produced from the resulting precipitated material. In such an embodiment, the drying process produces particles of the desired size, but very little, if any, additional process to produce the aggregate is required. In yet another embodiment, the precipitated material is further processed to produce the desired aggregate. For example, the precipitated material may be combined with fresh water under conditions sufficient to cause the precipitate to form a solid product, where the metastable carbonate compound present in the precipitate is: Convert to a stable form in fresh water. By adjusting the water content of the wet material, the porosity, final strength and density of the final aggregate may be adjusted. Typically, the wet cake will contain 40-60% water by volume. In order to obtain a denser aggregate, the wet cake should be less than 50% moisture, and in order to obtain a cake having a lower density, the moisture in the wet cake should be greater than 50%. After curing, the resulting solid product may be mechanically processed, for example, crushed by crushing or other methods, and classified to produce aggregates having desired properties such as size, specific shape, and the like. In these processes, the setting and machining steps may be performed in a substantially continuous manner or at different times. In certain embodiments, a large amount of precipitate may be stored in an outdoor environment where the precipitate may be exposed to the atmosphere. In the condensation process, the precipitate is poured into fresh water in a convenient manner, or naturally or intentionally exposed to rain, so that a condensed product can be produced. The product so set may then be mechanically processed as described above. After the precipitate is generated, the precipitate is processed to produce the desired aggregate. In some embodiments, the precipitate may be left outdoors where rainwater can be used as a fresh water source, thereby causing a rainwater stabilization reaction and The precipitate is hardened to form an aggregate.

  In one example of one embodiment of the present invention, the precipitate is transferred to a desired depth above the compressed surface using a belt conveyor and highway grader, for example up to 12 inches, such as 1-12 inches. For example, evenly spread until 6 to 12 inches. The sprayed material is then poured with fresh water at an appropriate rate, for example 1.5 gallons of water per cubic foot of sediment. The material is then compressed many times using a steel roller, such as that used to compress asphalt. Re-watering a weakly basic material on the surface and continuing until the material exhibits the desired chemical and mechanical properties, at which point the material is mechanically processed into aggregates by crushing.

  In an example of a further embodiment of the invention, the carbonate-containing precipitated material once separated from the precipitation reaction mixture is washed with fresh water and then subjected to a filter press to produce a filter cake with a solids content of 30-60%. . The filter cake is then mechanically compressed in a mold using any convenient means, such as a hydraulic press, at an appropriate pressure, for example, 5 to 5000 psi, for example 1000 to 5000 psi, to form a molded solid. For example, a rectangular brick is formed. Next, the solid material thus obtained is cured by, for example, leaving it outdoors or placing it in a chamber that gives high temperature and high humidity to them. The cured solid thus obtained is then used as it is as a building material or is crushed to produce an aggregate. A method of manufacturing such aggregate is described in US patent application Ser. No. 12 / 475,378 (filed May 29, 2009), the disclosure of which is hereby incorporated by reference. In the description).

  In processes involving the use of temperature and pressure, the dehydrated aqueous precipitate cake is generally first dried. The cake is then exposed to a combination of re-adding water and increasing the temperature and / or pressure for a predetermined time. The combination of amount of re-added water, temperature, pressure, and exposure time, as well as cake thickness, can be varied according to the composition of the starting material and the desired result. It will be appreciated that many different ways of exposing the material to temperature and pressure are described herein and any convenient method may be used. An example of a drying procedure is exposure at 40 ° C. for 24-48 hours, but the temperature and time may be increased or decreased as desired, for example, at 20-60 ° C. for 3-96 hours or longer. Good. Water is re-added to the desired percentage, such as 1% to 50%, such as 1% to 10%, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10% (w / w), for example, 5% (w / w), or 4-6% (w / w), or 3-7% (w / w). In some cases, the exact amount of water to be re-added is less important, such as materials stored outdoors and exposed to meteorological precipitation. The thickness and size of the cake may be determined as desired. The thickness can vary between 0.05 inches and 5 inches, such as between 0.1 and 2 inches, or 0.3 and 1 inches in some embodiments. In some embodiments, the cake thickness may be 0.5 inches to 6 feet or thicker. The cake is then exposed to elevated temperature and / or pressure for a predetermined time by any convenient method, such as a platen press using a heated platen. For example, heat for raising the temperature for the platen may be provided by heat from an industrial waste gas stream, such as a flue gas stream, for example. The temperature may be any suitable temperature. In general, the thicker the cake, the higher the temperature is desirable. For example, the temperature range is 40 to 150 ° C., for example 60 to 120 ° C., for example 70 to 110 ° C or 80-100 ° C. Similarly, the pressure may be any suitable pressure that will produce the desired result, but examples of pressure include 1000 to 100,000 pounds per square inch (psi), such as 2000 to 50,000 psi, or 2000 to 25,000 psi, or 2000 to 20,000 psi, or 3000 to 5000 psi. Finally, the time to compress the cake can also be any suitable time, for example, 1-100 seconds, or 1-100 minutes, or 1-50 minutes, or 2-25 minutes, or 1-10,000 days. It is. The hard tablet thus obtained is then cured, depending on the case, for example, by leaving it outdoors or placing it in a chamber that gives them high humidity and high temperature. Those hardened tablets, optionally cured, are then used as building materials as they are or are crushed to produce aggregates.

  One way to apply temperature and pressure is to stack dehydrated and dried slabs. For example, in such methods, the dehydrated precipitate may be dried, for example, using flue gas, for example, 1 inch to 10 feet thick, or 1 foot to 10 feet thick slab. Slabs are stacked on top of each other and pressure is applied, but the thicker the slab layer, the higher the pressure is obtained, for example, 10 to 1000 feet or more, such as 100 to 5000 feet. Depending on the desired result, it may be days, weeks, months, or even years, but after an appropriate amount of time, it has been urbanized from a certain level of the layer, eg from the bottom The slab is removed, for example, by quarrying and processed as desired to produce aggregate or other rock material.

  Another method for applying temperature and pressure is to use a press, as described in US patent application Ser. No. 12 / 475,378 (filed May 29, 2009). It is described in detail. Using a suitable press, eg a platen press, the desired temperature (eg using flue gas or other steps of the process to produce a precipitate, eg using heat supplied from an electrochemical process) The pressure may be applied for a desired time. A series of rollers may be used in a similar manner.

  Another method for exposing the cake to high temperature and pressure is by means of an extruder, such as a screw type extruder, and is also described in US patent application Ser. No. 12 / 475,378 (filing date, May 29, 2009). The extruder barrel is equipped to accept high temperatures, for example by means of a jacket, which can be supplied by, for example, flue gas. Extrusion may be used as a means to preheat and dry the feed prior to the pressurization operation. Such pressurization can be by compression mold means, through a roller, or a roller having a shaped indentation (which can provide virtually any desired shape of aggregate). Through, between belts that apply compression while moving, or by various other convenient methods. Alternatively, an extruder may be used to extrude the material through the die, press the material by forcing the material through the die, and give various desired shapes. In some embodiments, the carbonate mineral precipitate is mixed with fresh water and then placed in the feed section of a rotary screw extruder. The extruder and / or outlet die may be heated to further assist the process. The rotation of the screw carries the material along its length and compresses as the flight depth of the screw decreases. The extruder screw and barrel may further include a vent in the barrel, having a vacuum zone in the screw that coincides with the opening of the barrel vent. Especially in the case of heated extruders, these vent regions release steam from the material being transported, allowing removal of water from the material.

  The screwed material is then forced through the die section, which further compresses the material to form. Typical openings in the die can be circles, ellipses, squares, rectangles, trapezoids, etc., but any shape desired in the final aggregate can be made by adjusting the shape of the openings. I will. The material extruded from the die may be cut into various suitable lengths by any convenient method, such as a fly knife. A typical length can be from 0.05 inches to 6 inches, but can be lengths outside this range. Typical diameters can be 0.05 inches to 1.0 inches, but can be outside diameters in this range.

  The use of heated dissections may facilitate the formation of aggregates because it accelerates the conversion of carbonate minerals into a hard and stable form. In the case of a binder, a heating die may be used to cure or condense the binder. In the heating die section, temperatures of 100 ° C. to 600 ° C. are usually used. The heat for the heating die may be received, in whole or in part, from flue gas or other industrial gas used in the process of generating precipitates, in which case the flue gas is First sent to the die to transfer heat from the hot flue gas to the die.

  In yet other embodiments, the precipitate may be employed in situ or in situ molded structure fabrication. For example, roads, pavement areas, or other structures may be applied to a substrate such as, for example, the ground, roadbed, etc. May be made from the precipitate by hydrating the precipitate by exposure to water supplied or water injection. Hydration solidifies the precipitate to the desired in-situ or in-situ molded structure, such as roads, pavement areas, and the like. For example, if a thicker in-situ structure is desired, the process may be repeated.

System Aspects of the present invention further include a system for performing the method as described above, such as a processing plant or factory. The system of the present invention may include various configurations that enable the implementation of a specific manufacturing method of interest. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 1 ton / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 10 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 100 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 1000 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 10,000 tons / day.

  In certain embodiments, the system includes a source of an aqueous solution containing a divalent cation, such as a structure having an inlet for the aqueous solution. For example, the system may include a pipeline or similar feed of a divalent cation-containing aqueous solution, where the divalent cation-containing aqueous solution is brine, seawater, or fresh water. In some embodiments, the system includes a structure that has no inlet for divalent cations or has an inlet for water that contains a low concentration of divalent cations. In some embodiments, the structure and inlet are sufficient (with divalent cations, to produce more than 1, 10, 100, 1,000, or 10,000 tons / day of precipitated material. It is configured to supply water (with or without).

  In addition, the system will include a precipitation reactor in which water introduced into the precipitation reactor is used as precipitation conditions (as described above) for carbonate compounds to produce a precipitated material and a supernatant. In some embodiments, the precipitation reactor is sufficient to produce more than 1, 10, 100, 1,000, or 10,000 tons / day of precipitated material (with divalent cations, or It is configured so that water can be supplied. The precipitation reactor may further be configured to include some of a variety of different elements, for example: a temperature control element (eg, configured to heat water to a desired temperature). Compound addition elements (eg, configured to introduce divalent cations, proton scavengers, etc. into the precipitation reaction mixture), electrolysis elements (eg, cathode, anode, etc.), and the like.

  The system further includes a source of CO2 and a waste source of metal oxides, as well as a source of water (possibly containing a divalent cation-containing aqueous solution such as brine or seawater) and a precipitation reactor. Components for combination before or at some point in the precipitation reactor are included. Thus, the precipitation system may include, for example, an independent source of CO 2, in which case the system may have an aqueous solution of divalent cations and / or supernatant at some time during the process, It is configured to be employed in embodiments that are contacted with a carbon dioxide source. This source can be any of those previously described (eg, waste feed from an industrial power plant) and gas contact can be achieved, for example, in US provisional application 61/178475 (application). (May 14, 2009) may be implemented in a gas-liquid contact device (this application is hereby incorporated by reference in its entirety). In some embodiments, the gas-liquid contactor is configured to be in contact with sufficient CO2 to produce more than 1, 10, 100, 1,000, or 10,000 tons / day of precipitated material. Has been.

  The gaseous waste stream may be sent from the industrial plant to the precipitation site in a variety of convenient ways to transport the gaseous waste stream from the industrial plant to the precipitation plant. In some embodiments, the gaseous waste stream runs from an industrial plant site (eg, an industrial plant flue) to one or more locations of a precipitation site ( For example, it is sent using a duct. The gaseous waste stream source may be at a location remote from the site of precipitation, for example, the gaseous waste stream source may be more than one mile, for example 10 miles from the site of precipitation. For example, the distance may be 100 miles or more. For example, a gaseous waste stream may be transported from a remote industrial plant to a precipitation site via a CO2 gas transport system (eg, a pipeline). The CO2-containing gas generated in the industrial plant must be processed (eg, removal of other components) before reaching the precipitation site (ie, the site where precipitation and / or aggregate production takes place). It may or may not be processed. In yet another example, the source of the gaseous waste stream is in the vicinity of the precipitation site. For example, a power plant where the precipitation site is integrated with a gaseous waste stream source, for example, with a precipitation reactor for precipitating precipitated material that can be used to produce aggregates It is.

  As previously explained, the gaseous waste stream may be obtained from an industrial plant flue or similar structure. In these embodiments, a line (eg, duct) is connected to the flue through which gas is removed from the flue and transported to an appropriate location in the precipitation system. Depending on the specific structure of the precipitation system at the point where the gaseous waste stream is utilized, the location of the source from which the gaseous waste stream is obtained (eg, suitable or desired temperature) (For the purpose of obtaining a waste stream). Thus, in certain embodiments, if a gaseous waste stream having a temperature in the range of 0 ° C. to 1800 ° C., such as 60 ° C. to 700 ° C. is desired, the flue gas is passed through a boiler or gas It may be removed at the turbine, kiln exit point, or at a point where the desired temperature of the power plant or chimney is obtained. If desired, the flue gas is maintained at a temperature above the dew point (eg, 125 ° C.) to avoid condensation and related problems. If the temperature cannot be maintained above the dew point, use a duct lined with stainless steel, fluorocarbon (eg poly (tetrafluoroethylene)), taking measures to prevent the adverse effects of condensation, with water Dilute, adjust pH, etc.) to prevent the duct from deteriorating rapidly.

  If the salt water source used to make the carbonate compound composition in the system is seawater, the inlet is in fluid communication with the seawater source, for example, from the ocean water to the onshore system. Pipelines or feeds, or the inlet portion is in the hull of a ship, eg the system is part of a ship, eg an offshore system.

  The system further includes a liquid separator for separating the carbonate-containing precipitated material from the original reaction mixture from which it was produced. As described in detail in US Provisional Patent Application No. 61/170086, filed April 16, 2109, incorporated herein by reference, liquid-solid separators. For example, an improvement of either an Euramat Extreme-Separator (“ExSep”) liquid-solid separator, a Xerox PARC spiral concentrator, or an Euramat ExSep or Xerox PARC spiral concentrator can be used as a precipitating substance from a precipitation reaction mixture. It is useful for separating. In certain embodiments, the separator is a drying station for drying the precipitated carbonate mineral composition produced at the carbonate mineral precipitation station. Depending on the particular drying procedure of the system, the drying station may include filtering elements, freeze drying structures, spray drying structures, etc., which are described in more detail below.

  In certain embodiments, the system will further include a station for preparing building materials such as cement or aggregate from the precipitate. See, for example, the following patents: US patent application Ser. No. 12 / 126,776 (Title of Invention: “Hydraulic Components Compositing Carbonates Compositions”, filing date, May 23, 2008), and US Patent Provisional. Application No. 61 / 056,972 (Title of Invention: “CO2 Requesting Aggregate, and Methods of Making and Using the Same”, filing date, May 23, 2008) (see disclosure of these applications) In this specification).

  As explained earlier, this system may be on land or at sea. For example, the system may be a terrestrial system, for example in a coastal area close to a seawater source, or inland and piped water from a salt water source, such as the ocean, to the system. It may be a thing. Alternatively, the system may be a water system, i.e. a system that is on or in water. Such a system may be present on a ship, on a marine platform, etc., if desired.

  FIG. 1 illustrates a typical power plant process that burns coal and removes waste such as ash and sulfur. When the coal 500 is burned in the steam boiler 501, the generated steam drives the turbine generator to generate electric power. Combustion of coal produces flue gas 502, which includes CO2, SOx, NOx, Hg, and even fly ash. Coal combustion also produces bottom ash 510, which may be sent to landfills or used as low value aggregate. The flue gas 502 passes through a separation device 520, typically an electrostatic precipitator, where fly ash 530 is removed from the flue gas 502. Depending on the type of combustion and the type of coal, fly ash 530 may be used advantageously in concrete, but more generally is landfilled.

  Fan 540 sends sulfur-containing flue gas 521 to FGD tank 550 where flue gas exposure treatment is performed on lime slurry 553 prepared from water 551 and calcined lime 552. While lime calcination releases CO2 into the atmosphere, lime production releases 1 mole of CO2 per mole of lime used. In the FGD tank 550, the lime 552 combines with SOx from the flue gas 521 to generate gypsum (CaSO4). Thus, one molecule of CO2 was released into the atmosphere from lime calcination per molecule of sulfur removed from the flue gas.

  The sulfur-free flue gas 556 is sent from the FGD tank 550 through the pipe to the chimney 560 and released into the atmosphere as a gas 580. Prior to the release, further processing is performed to remove NOx, Hg, etc. May be. Note that the gas 580 released to the atmosphere contains most if not all of the CO 2 generated by the combustion of the coal 500.

  In the FGD tank 550, the calcined lime slurry 553 reacts with the sulfur-containing flue gas 521 to produce a gypsum slurry 554, which is sent to the hydrocyclone 570 by means of the pump 555. The hydrocyclone 570 removes the water 571 from the slurry 554 to produce a more concentrated gypsum slurry 579, which is sent to the filter 580 for further dehydration. The water removed by the hydrocyclone 570 and the filter 580 is sent to the reclaimed water tank 572, where excess solids are settled and sent to the landfill 511. Waste water 574 is discharged, but some reclaimed water 573 is sent back to the FGD tank 550. The filter cake 581 removed from the filter 580 is sent to a dryer 583 where water is removed to produce a dried gypsum powder 590. The gypsum powder 590 may be sent to the landfill 511 or may be used to produce building materials such as wallboard.

  FIG. 2 shows an example of one embodiment of the present invention where CO2, fly ash, NOx, SOx, Hg and other contaminants are utilized as reactants in the carbonate compound precipitation process, Their components are removed, for example, they are used in hydraulic cement to contain them in the building material environment. In this example, fly ash and bottom ash are utilized as reactants to lower the pH while providing beneficial co-reactive cations such as silicon and aluminum.

  When the coal 600 is burned in the steam boiler 601, the generated steam drives the turbine generator to generate electric power. Combustion of coal produces flue gas 602, which includes CO2, SOx, NOx, Hg, and even fly ash. In this embodiment, the coal used is a high sulfur subbituminous coal, which, although available inexpensively, generates large amounts of SOx and other contaminants. Flue gas 602, bottom ash 610, seawater 620, and in some embodiments additional alkali source 625, are charged to reactor 630 where a carbonate mineral precipitation process is performed to produce slurry 631. .

  The slurry 631 is pumped to the drying system 650 via a pump 640, which in some embodiments includes a filtration step followed by spray drying. The water 651 separated by the drying system 650 is discharged, and at the same time, the clean gas 680 that can be released into the atmosphere is discharged. Solids or powders 660 obtained from the drying system 650 are utilized as hydraulic cement to produce building materials, which include CO2, SOx, and in some embodiments other contaminants such as Mercury and / or NOx is effectively contained in the building material environment.

  Thus, what is provided is a system that includes a lime slaker, a precipitation reactor, and a liquid-solid separator adapted to sanctify a metal oxide waste source, wherein the precipitation The reactor is operably connected to both the lime slaker and the liquid-solid separator, and further wherein the system is configured to produce carbonate-containing precipitated material in an amount greater than 1 ton / day. ing. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 10 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 100 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 1000 tons / day. In some embodiments, the system is configured to produce carbonate-containing precipitated material in an amount greater than 10,000 tons / day. In some embodiments, the lime slaker is selected from a slurry stay lime slaker, a paste lime slaker, and a ball mill lime slaker. In some embodiments, the system further includes a source of carbon dioxide. In some embodiments, the carbon dioxide source is from a coal-fired power plant or a cement plant. In some embodiments, the system further includes a source of proton scavenger. In some embodiments, the system further includes a source of divalent cations. In some embodiments, the system further includes a building material generation unit configured to generate building material from the solid product of the liquid-solid separator.

  The following examples are intended to provide those skilled in the art with a complete disclosure and description of how to make and use the present invention, but they limit the scope of what the inventors regard as their invention. It is not intended to be made, nor is it intended to state that the experiments shown below are all of the experiments that have been performed, or that only this has been done. While still accurate with respect to numerical values used (eg, amounts, temperatures, etc.), some experimental error and deviation should be allowed. Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees Centigrade, and pressure is at or near atmospheric.

  Using the following analytical instruments and methods for using them, the characteristics of the substances obtained in the following examples were analyzed.

  Coulometer: 2.0N perchloric acid (HClO4) was used to acidify liquid and solid carbon-containing samples to generate carbon dioxide gas in the gas stream, then pH 3.0 3 (w After scrubbing to / v)% silver nitrate to remove all generated sulfur gas, analysis was performed with an inorganic carbon coulometer (UIC Inc, model CM5015). Cement, fly ash, and seawater samples were heated using a heating block after the addition of perchloric acid to promote digestion of the samples.

  Brunauer-Emmett-Teller (“BET”) specific surface area: Specific surface area (SSA) measurements were by surface absorption using dinitrogen (BET method) .The SSA of the dried sample was measured by Flowprep ™ 060 sample removal. Samples were prepared using a gas system and then measured using a Micromeritics Tristar ™ II 3020 Specific Surface Area and Porosity Analyzer. Degassing and simultaneous exposure to a flow of dinitrogen gas to remove residual water vapor and other adsorbents from the surface of the sample, and then purge the purge gas in the sample holder under vacuum; Sun The sample was cooled and then exposed to dinitrogen gas with increasing pressure (relative to the thickness of the adsorbed film), and after the surface was covered, the pressure in the sample holder was systematically reduced. As a result, dinitrogen was released from the surface of the particles, and the desorbed gas was measured and converted into a total surface area measurement value.

  Particle Size Analysis (“PSA”): Particle size analysis and distribution were measured using a static light scattering method. Dried particles were suspended in isopropyl alcohol and analyzed using a Horiba Particle Size Distribution Analyzer (Model LA-950V2) in a dual wavelength / laser configuration. Using Mie scattering theory, the number of particles was calculated as a function of the size fraction between 0.1 mm and 1000 mm.

  Powder X-ray Diffraction (“XRD”): Powder X-ray diffraction is measured using Rigaku Miniflex ™ (Rigaku) to identify crystalline phases and the mass of various identifiable sample phases. I guessed the fraction. The dried solid sample was manually pulverized into a fine powder and placed on a sample holder. The X-ray source was a copper anode (Cu kα), and the output was 30 kV and 15 mA. X-rays were scanned in the range of 5 to 90 degrees (2θ), the scan speed was 2 degrees (2θ) / min, and the step size was 0.01 degrees (2θ) / step. X-ray diffraction profiles were analyzed by a modified Rietveld method using Jade ™ (version 9, Material Data Inc. (MDI)) of X-ray diffraction pattern analysis software.

Fourier Transform Infrared (“FT-IR”) spectroscopy: FT-IR analysis was performed on a Nicolet 380 fitted with a Smart Diffuse Reflectance module. All samples were weighed to 3.5 ± 0.5 mg, manually ground with 0.5 g KBr, then pressurized and averaged with a 5 minute nitrogen purge before loading into FT-IR Made it. Spectra were recorded in the range of 400-4000 cm- ¹ .

  Scanning Electron Microscopy ("SEM"): SEM was performed on a Hitachi TM-1000 tungsten filament tabletop microscope using a fixed acceleration voltage of 15 kV, working pressure of 30-65 Pa, and a single BSE semiconductor detector. The solid sample was fixed to the stage using a carbon-based adhesive. Liquid samples were analyzed after vacuum drying on a graphite stage.

  Chloride concentration: Chloride concentration was measured using a Chloride QuanTab® Test Strips (Product No. 2751340) with a test range of 300-6000 mg chloride / L-solution, 100-200 ppm intervals.

Example 1. Examination of pH of fly ash Experiment In a glass beaker, 500 mL of seawater (initial pH = 8.01) was continuously stirred using a magnetic stir bar. The pH and temperature of the reaction were continuously monitored. Class F fly ash (about 10% CaO) was added stepwise as a powder to allow the pH to reach equilibrium during the addition.

B. Results and Discussion (The amount of fly ash on the list is the cumulative total, that is, the total amount added at that point in the experiment.)

  After adding 5.00 g of fly ash, the pH reached 9.00.

  Raising the pH of the seawater required much more fly ash than with distilled water. The first increase in pH (from pH 8 to pH 9) required much less fly ash compared to subsequently increasing the pH by the same magnitude. For many reactions, the pH remained fairly stable at about 9.7. The rate of pH increased after about 10. It was also noticed that the pH dropped initially when fly ash was added. This decrease in pH is quickly countered by the effect of calcium hydroxide. SEM images of the vacuum dried slurry from the reaction indicated that some of the fly ash vacancies may have been partially dissolved. The remaining vacancies also seemed to be encased in the cementitious material.

C. Conclusion In fresh water (distilled water), a small amount of Class F fly ash (less than 1 g / L) was immediately seen to increase the pH from 7 (neutral) to about 11. The biggest reason that only a small amount is needed to raise the pH seems to be that the distilled water is not buffered. Seawater is strongly buffered by the carbonate system, so much more fly ash is required to raise the pH level as well.

Example 2: Precipitated material using fly ash as source of divalent cations and proton scavenger Consumption 1. Fly ash (322.04 g FAF11-001) was weighed into a 500 mL plastic reaction vessel.
2. Deionized water (320.92 g) was added to the reaction vessel so that the fly ash to water ratio was 1: 1.
3. The resulting mixture was stirred to a homogeneous slurry.
4). The reaction vessel was capped and sealed with tape.
5. The slurry was rotated for 24 hours.
B. Precipitation Deionized water (680 mL, pH 7.13) was added to a 2 L plastic reaction vessel with a large stirrer bar and stirred at 250 rpm.
2. Gradually adding the dehydrated slurry with stirring gave a reaction mixture that was at a concentration of about 320 g fly ash / L.
3. Stirring was continued until the pH level reached stability (pH 12.40).
4). Using a sparger located as low as possible in the reaction mixture (not disturbing the stirrer bar), 15% CO2 in the compressed air was introduced (CO2: 0.4 scfh, compressed air: 2.1 scfh) , Total: 2.5 scfh).
5. The reaction vessel was covered but left a slight gap for the gas tube and pH probe.
6). The pH was monitored and recorded over 5 hours.
7). After adding enough CO2 (ie, about 2 equivalents based on CaO / MgO in fly ash as measured by XRF) to the reaction slurry, stop blowing CO2 (by withdrawing the sparger), The reaction vessel was sealed and the precipitation reaction mixture was allowed to stir at 250 rpm overnight.

Process 1. The pH of the precipitation reaction mixture measured after stirring overnight was pH 8.37.
2. Stirring was stopped and the precipitation reaction mixture was filtered.
3. The resulting precipitated material was dried at 50 ° C. overnight.
4). The resulting supernatant was collected.

Analysis 1. The precipitated material was analyzed by SEM, XRD, TGA, coulometric analysis, and FT-IR. FIG. 3 is an SEM image of the precipitated material magnified 1000, 2500, and 6000 times. FIG. 4 provides an XRD of the precipitated material. FIG. 5 provides a TGA of the precipitated material. Coulometric analysis showed that the precipitated material contained 1.795% carbon.
2. The supernatant was analyzed using alkalinity and hardness.

Example 3: Precipitation material procedure using cement kiln dust as source of divalent cations and proton scavenger Consumption 1. Cement kiln dust (318.01 g) was weighed into a 500 mL plastic reaction vessel.
2. Deionized water (319.21 g) was added to the reaction vessel so that the ratio of cement kiln dust to water was 1: 1.
3. The resulting mixture was stirred to a homogeneous slurry.
4). The reaction vessel was capped and sealed with tape.
5. The slurry was rotated for 18 hours.
B. Precipitation Combining deionized water (680 mL) with a homogeneous slurry of cement kiln dust in a 2 L plastic reaction vessel with a large stirrer bar gives a reaction mixture containing about 318 g cement kiln dust per liter. It was.
2. The reaction mixture was stirred at 250 rpm until the appropriate pH level (pH 12.41) was reached.
3. Using a sparger located as low as possible in the reaction mixture (not disturbing the stirrer bar), 15% CO2 in the compressed air was introduced (CO2: 0.4 scfh, compressed air: 2.1 scfh) , Total: 2.5 scfh).
4). The reaction vessel was covered but left a slight gap for the gas tube and pH probe.
5. 15% CO2 in compressed air was bubbled through the reaction mixture overnight.
6). The CO2 blowing was stopped (by withdrawing the sparger), the reaction vessel was sealed, and the precipitation reaction mixture was allowed to stir at 250 rpm overnight.

Process 1. The pH of the precipitation reaction mixture measured after stirring overnight was pH 6.88.
2. Stirring was stopped and the precipitation reaction mixture was filtered.
3. The resulting precipitated material was dried at 50 ° C. overnight.
4). The resulting supernatant was collected.

Analysis 1. The precipitated material was analyzed by SEM, XRD, TGA, coulometric analysis, and percent soluble chloride. FIG. 6 provides an SEM image of the precipitated material magnified 2,500 times. FIG. 7 provides an XRD of the precipitated material. FIG. 8 provides a TGA of the precipitated material. Coulometric analysis showed that the precipitated material contained 7.40% carbon. The percent soluble chloride in the precipitated material was found to be 2.916% soluble chloride.
2. The supernatant was analyzed using alkalinity and hardness.

Example 4: Precipitation Material Procedure Using Cement Kiln Dust as Source of Divalent Cations and Proton Remover Cement kiln dust (80 g) was weighed into a 1.5 L plastic reaction vessel.
2. Deionized water (1 L) was added to the reaction vessel and the resulting mixture was stirred at 250 rpm (pH 12.45).
3. A sparger provided at the bottom of the reaction mixture using an adsorption cup was used to introduce 15% CO2 in compressed air (CO2: 0.3 scfh, compressed air: 2.0 scfh, total: 2.3 scfh).
4). The reaction vessel was covered but left a slight gap for the gas and pH probe.
5. The pH was monitored and recorded over about 4 hours.
6). After adding sufficient CO2 to the precipitation reaction mixture (ie, approximately 2 equivalents based on CaO / MgO in cement kiln dust as measured by XRF), CO2 blowing was stopped and the reaction vessel was sealed. The precipitation reaction mixture was allowed to stir at 250 rpm overnight.

Sample processing After stirring overnight, the pH of the precipitation reaction mixture was measured.
2. Stirring was stopped and the precipitation reaction mixture was filtered.
3. The resulting precipitated material was dried at 40 ° C. overnight.
4). The resulting supernatant was collected.

Analysis 1. The precipitated material was analyzed by SEM, FT-IR, and coulometric analysis. FIG. 9 provides an SEM image of the oven dried precipitate material magnified 2,500 times. FIG. 10 is an FT-IR of the oven dried precipitate material. Coulometric analysis showed that the precipitated material contained 7.75% carbon.

Example 5 FIG. Measurement of δ ¹³ C values of precipitated and starting materials In this experiment, a mixture of bottled sulfur dioxide (SO 2) gas and bottled carbon dioxide (CO 2) gas and fly ash as a waste source of metal oxides Was used to prepare a carbonate-containing precipitated material. This procedure was performed in a closed container.

  The starting material was a mixture of commercially bottled SO2 and CO2 gas (SO2 / CO2 gas, or "simulated flue gas"), deionized water, and fly ash as a source of metal oxide waste.

  The vessel was filled with deionized water. The dehydrated fly ash is added to the deionized water to give a (alkaline) pH and divalent cation concentration suitable for precipitating carbonate-containing precipitated material without releasing CO2 into the atmosphere. It was. SO2 / CO2 gas was blown at a rate and time suitable for precipitating the precipitated material from the alkaline solution. After leaving the reaction components for a sufficient amount of time to interact, the precipitated material was separated from the remaining solution (“precipitation reaction mixture”) to obtain a wet precipitated material and a supernatant.

The δ ¹³ C values of the process starting material, the precipitated material, and the supernatant were measured. The analytical system used was from Los Gatos Research and used direct absorptiometry to give δ ¹³ C and concentration data for a CO 2 dry gas ranging from 2% to 20%. The instrument was calibrated using standard 5% CO2 gas with a known isotope composition, and CO2 generated from samples of travertine and IAEA marble # 20 digested in 2M perchloric acid. Measurements yielded numerical values that were within acceptable measurement error ranges from literature values. The CO2 source gas was sampled using a syringe. The CO 2 gas is passed through a gas dryer (Perma Pure MD Gas Dryer, Model MD-110-48F-4, made of Nafion® polymer), and then a desktop commercial carbon isotope analysis system Introduced in. The solid sample was first digested with heated perchloric acid (2M HClO4). CO2 gas was generated from the closed digestion system and then passed through the gas dryer. From there, gas was collected and injected into the analysis system to obtain a δ ¹³ C value. Similarly, the supernatant was also digested to generate CO2 gas, which was then dried and then introduced into the analytical instrument field to obtain δ ¹³ C data.

Measurements from analysis of SO2 / CO2 gas, metal oxide waste source (ie, fly ash), carbonate-containing precipitation material, and supernatant are shown in Table 5. The δ ¹³ C values in the precipitated material and the supernatant are -15.88 ‰ and -11.70 ‰, respectively. The δ ¹³ C value of any product of the reaction includes SO 2 / CO 2 gas (δ ¹³ C = -12.45 ‰) and fly ash (some carbon that is not completely burned to gas) (δ ¹³ C = −17.46 ‰) is incorporated. Since fly ash, which itself is a product from the combustion of fossil fuels, had a negative δ ¹³ C greater than the CO 2 used, the overall δ ¹³ C value of the precipitated material is CO 2 itself. This reflects that the negative value is larger than the value of. This example shows that the δ ¹³ C value may be used to identify the natural source of carbon in the carbonate-containing composition material.

Example 6 Manufacturing of cement A. Cement # 1
1. Precipitation of raw material Seawater collected with 1000 mL Santa Cruz Harbor (pH = 8.07, T = 20.3 ° C.). Add 1M NaOH dropwise to seawater. At about pH 10, precipitate formation began (confirmed by the reaction mixture becoming cloudy). Even with the continued addition of NaOH, the pH did not rise above about pH 10.15. When the base addition was stopped, the pH dropped to a lower pH value. As the base was added, the solution gradually became cloudy, indicating that precipitation was progressing. After about 20 minutes, the pH drop stopped and the base addition was stopped. The precipitation reaction mixture was then filtered through a Watman 410 1 μm filter and the filtrate was lyophilized.

2. Cement The lyophilized powder produced according to the immediately preceding description is hydrated by the dropwise addition of fresh distilled water to form a cement paste, which is mixed for about 30 seconds with a smoked mortar and pestle, The cement paste had a toothpaste consistency. When the pH of the paste was measured using pH test paper, it was found that the pH was between pH 11 and pH 12. The cement paste was molded into spheres, left in a mortar, and sealed (with mortar) in a suitable plastic bag for 1 day. After one day, the cement spheres became hard and had an oval shape due to slumping while drying.

B. Cement # 2
Cement powder composed of amorphous calcium magnesium carbonate (AMCC), silica fume, vaterite, and water talc (magnesium hydroxide) was blended in the following mass ratio: 3AMCC: 5 silica fume: 7 vaterite: 0.2 water talc .

  The AMCC was precipitated from a by-product of a seawater desalination plant that was concentrated to a salinity of 46,000 ppm at ambient temperature. By adding sodium hydroxide to the concentrated aqueous by-product until the pH begins to precipitate above 11 and adding sodium hydroxide so that the pH can be maintained at pH 11, AMCC Caused precipitation. The AMCC precipitate was continuously filtered and removed from the system, lyophilized and stored.

  Silica fume was obtained from a commercial source.

  Vaterite was precipitated from seawater stabilized with 2 μmol / kg LaCl 3 at a temperature of about 45 ° C. The seawater processed by the desalinator was already 5-10 degrees warmer than the seawater taken. If required, further heating to 45 ° C. may be accomplished by passing the seawater through the solar panel prior to precipitating the vaterite.

  Water talc was also obtained from a commercial source.

  Water is added to the above mixture so that the water: cement mass ratio is 0.4: 1.0 (L / S = 0.4) to form a useful paste having an alkaline pH. It was. The paste thickens after about 1 hour and sets by 2 hours to become a hardened cement. With that cement, more than 90% of its compressive strength was obtained after several weeks.

C. Cement # 3
Cement powder consisting of aragonite, amorphous calcium magnesium carbonate (AMCC), and fly ash was blended in the following mass ratios: 4 aragonite: 3AMCC: 3 silica fume: 0.4 Betonies Clay .

  The aragonite was precipitated from a by-product of a seawater desalination plant that was concentrated to a salinity of 46,000 ppm at 60 ° C. The seawater processed by the desalinator was already 5-10 degrees warmer than the seawater taken. If required, further heating to 60 ° C. may be accomplished by passing the water through the solar panel before allowing the stones to settle. Sodium hydroxide was added to the water until the pH was above 9 until precipitation was initiated, and sodium hydroxide was added to maintain the pH at pH 9 to cause the precipitation. . The aragonite precipitate was removed from the system by continuous filtration, lyophilized and stored.

  The AMCC is precipitated from a by-product of a seawater desalination plant that is concentrated to a salinity of 46,000 ppm at ambient temperature. Sodium hydroxide was added to the water and added until precipitation was initiated such that the pH exceeded 11, and the precipitation was caused by adding sodium hydroxide so that the pH could be maintained at pH 11. . The AMCC precipitate was continuously filtered and removed from the system, lyophilized and stored.

  Fly ash was obtained from a coal-fired thermal power plant source.

  Water is added to the above mixture so that the water: cement mass ratio is 0.25: 1.0 (L / S = 0.25) to form a useful paste having an alkaline pH. It was. The paste thickened after about 1 hour and set to about hardened cement by about 2 hours. With the cement, more than about 90% of its compressive strength was obtained after several weeks.

Example 7: Compressive strength of hydraulic cement mortar cubes containing precipitated material Hydraulic cement mortar cubes were prepared and tested for compressive strength according to ASTM C109. As can be seen in Table 6 below, the cubes of hydraulic cement mortar were divided into 100% OPC, 80% OPC4-1 + 20% fly ash, 80% OPC4-1 + 1 + 20% PPT1, 80% OPC4-1 + 20% PPT2, and 50. Prepared with a composition of% OPC + 50% PPT2, where PPT1 and PPT2 are the precipitated materials prepared in Example 2. The blend of OPC and precipitated material was mixed dry and then combined with water (w / c = 0.50). 100% OPC was also combined with water with a water / cement ratio of 0.50.

  As is evident from the data shown in Table 6, the compressive strength of hydraulic cement mortar cubes containing precipitated material is generally equal to or better than that of OPC alone hydraulic cement mortar cubes. is there.

Example 8: Preparation of Aggregate from Precipitated Material Clean the steel mold of a Wabash hydraulic press (Model No .: 75-24-2TRM; ca. 1974), preheat the platen, and platen surface (mold (Including cavity and punch) at 90 ° C. for a minimum of 1 hour.

  Some of the precipitated material filter cakes from Example 1 were oven dried in a sheet pan at 40 ° C. for 48 hours and then crushed in a blender so that the crushed material was no. Passed 8 sieves. The ground material was then mixed with water to give a mixture where 90-95% was solids and the remainder added water (5-10%).

  A 4 inch x 8 inch mold in a Wabash press was filled with the wet mixture of ground precipitate material and 64 tons (4000 psi) of pressure was applied to the precipitate material for about 10 seconds. The pressure was then released and the mold was reopened. The precipitated material stuck to the side of the mold was peeled off and moved to the center of the mold. The mold was then closed again and 64 tons of pressure was applied for a total of 5 minutes. The pressure was then released, the mold was reopened, and the pressurized precipitated material (now an aggregate) was removed from the mold and allowed to cool under environmental conditions. In some cases, the aggregate was transferred from the mold to a drying rack in a 110 ° C. oven, allowed to dry for 16 hours, and then allowed to cool under environmental conditions.

  Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will depart from the spirit and scope of the appended claims in view of the teachings of the present invention. It will be readily apparent to those skilled in the art that certain changes and modifications can be made. Accordingly, the foregoing description is merely illustrative of the principles of the invention. Those skilled in the art will be able to embody the principles of the invention and devise various assemblies that fall within the spirit and scope of the invention, even if not explicitly described or explicitly described herein. It will be appreciated. In addition, all examples and condition descriptions cited herein primarily help the reader to understand the principles of the invention for advancing technology and the concepts contributed by the inventors. It is intended that this should be taken as illustrative and not limiting to such specific cited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. ing. Further, such equivalents include both currently known equivalents as well as equivalents that will be developed in the future, i.e., various developed elements that perform the same function regardless of structure. It is intended to be included. Accordingly, it is not intended that the scope of the invention be limited to the exemplary embodiments that are explicitly described and described herein. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of those claims and their equivalents are covered thereby. It is that.

Claims (79)

a) contacting the aqueous solution with a source of metal oxide from an industrial process;
b) charging the aqueous solution with carbon dioxide from a source of carbon dioxide from an industrial process; and c) subjecting the aqueous solution to precipitation conditions at atmospheric pressure to produce a carbonate-containing precipitation material;
Including a method.   The method of claim 1, wherein the metal oxide source and the carbon dioxide source are from the same industrial process.   The method of claim 2, wherein contacting the aqueous solution with the metal oxide source is performed prior to charging the aqueous solution with a carbon dioxide source.   The method of claim 2, wherein contacting the aqueous solution with the source of metal oxide is performed simultaneously with charging the aqueous solution with a source of carbon dioxide.   3. The method of claim 2, wherein contacting the aqueous solution with the metal oxide source, charging the aqueous solution with a carbon dioxide source, and placing the aqueous solution in precipitation conditions are performed simultaneously. the method of.   The method according to claim 3, wherein the metal oxide supply source and the carbon dioxide supply source are supplied from the same waste stream.   The method of claim 6, wherein the waste stream is flue gas from a coal-fired power plant.   The method according to claim 7, wherein the coal-fired power plant is a lignite-fired power plant.   The method of claim 6, wherein the waste stream is kiln emissions from a cement plant.   The method of claim 7, wherein the source of metal oxide is fly ash.   The method of claim 9, wherein the source of metal oxide is cement kiln dust.   The method of claim 6, wherein the waste stream further comprises SOx, NOx, mercury, or various combinations thereof.   The method of claim 2, wherein the source of metal oxide further provides a divalent cation for generating a precipitated material.   The method of claim 2, wherein both the metal oxide source and the aqueous solution include divalent cations for generating the precipitated material.   15. The method of claim 14, wherein the source of metal oxide is fly ash or cement kiln dust.   The method of claim 15, wherein the aqueous solution comprises brine, seawater, or fresh water. The method of claim 16, wherein the divalent cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof.   The method of claim 2, wherein the source of metal oxide provides a proton scavenger to produce the precipitated material.   The method of claim 18, wherein the source of metal oxide hydrates CaO, MgO, or a combination thereof in the aqueous solution to provide a proton scavenger.   The method of claim 18, wherein the source of metal oxide further provides silica.   The method of claim 18, wherein the source of metal oxide further provides alumina.   The method of claim 18, wherein the source of metal oxide further provides ferric oxide.   19. The method of claim 18, wherein the red mud or brown mud from bauxite processing further provides a proton scavenger.   19. The method of claim 18, wherein the electrochemical method affecting proton removal further provides for the formation of a precipitated material.   The method of claim 2, further comprising separating the precipitated material from the aqueous solution from which the precipitated material is produced.   26. The method of claim 25, wherein the precipitated material comprises CaCO3.   27. The method of claim 26, wherein the CaCO3 includes calcite, aragonite, vaterite, or combinations thereof.   27. The method of claim 26, wherein the precipitation material further comprises MgCO3.   29. The method of claim 28, wherein the CaCO3 comprises aragonite and the MgCO3 comprises neskehonite.   26. The method of claim 25, further comprising processing the precipitated material to form a building material.   32. The method of claim 30, wherein the building material is hydraulic cement.   32. The method of claim 30, wherein the building material is pozzolanic cement.   32. The method of claim 30, wherein the building material is aggregate. a) contacting the aqueous solution with a waste stream comprising carbon dioxide and a source comprising a metal oxide; and b) subjecting the aqueous solution to precipitation conditions to produce a carbonate-containing precipitated material;
Including a method.   35. The method of claim 34, wherein the waste stream is flue gas from a coal-fired power plant.   36. The method of claim 35, wherein the coal-fired power plant is a lignite-fired power plant.   36. The method of claim 35, wherein the metal oxide source is fly ash.   35. The method of claim 34, wherein the waste stream is kiln emissions from a cement plant.   40. The method of claim 38, wherein the metal oxide source is cement kiln dust.   39. The method of claim 35 or 38, wherein the waste stream further comprises SOx, NOx, mercury, or various combinations thereof.   41. The method of claim 40, wherein a divalent cation for generating the precipitated material is provided by the source of the metal oxide, the aqueous solution, or a combination thereof.   42. The method of claim 41, wherein the aqueous solution comprises brine, seawater, or fresh water. 43. The method of claim 42, wherein the divalent cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof.   42. The method of claim 41, wherein the source of metal oxide further provides a proton scavenger to produce the precipitated material.   45. The method of claim 44, wherein the source of metal oxide hydrates CaO, MgO, or a combination thereof in the aqueous solution to provide a proton scavenger.   35. The method of claim 34, wherein the source of metal oxide further provides silica.   35. The method of claim 34, wherein the source of metal oxide further provides alumina.   35. The method of claim 34, wherein the source of metal oxide further provides ferric oxide.   45. The method of claim 44, wherein the red mud or brown mud from bauxite processing further provides a proton scavenger.   45. The method of claim 44, wherein the electrochemical method affecting proton removal further provides for the formation of a precipitated material.   35. The method of claim 34, wherein the precipitated material comprises CaCO3.   52. The method of claim 51, wherein the CaCO3 comprises calcite, aragonite, vaterite, or combinations thereof.   35. The method of claim 34, further comprising separating the precipitated material from the aqueous solution from which the precipitated material is produced.   54. The method of claim 53, further comprising processing the precipitated material to form a building material.   55. The method of claim 54, wherein the building material is hydraulic cement.   55. The method of claim 54, wherein the building material is pozzolanic cement.   55. The method of claim 54, wherein the building material is aggregate. A siliceous composition comprising synthetic calcium carbonate,
The calcium carbonate is present in at least two forms selected from calcite, aragonite, and vaterite;
Composition.   59. The composition of claim 58, wherein the at least two forms of calcium carbonate are calcite and aragonite.   60. The composition of claim 59, wherein calcite and aragonite are present in a ratio of 20: 1.   61. The composition of claim 60, wherein the calcium carbonate and silica are present in a carbonate to silica ratio of at least 1: 2.   61. The composition of claim 60, wherein 75% of the silica is amorphous silica having a particle size of less than 45 microns.   61. The composition of claim 60, wherein the silica particles are fully or partially encapsulated with synthetic calcium carbonate or synthetic magnesium carbonate. A siliceous composition comprising synthetic calcium carbonate and synthetic magnesium carbonate,
The calcium carbonate is present in at least one form selected from calcite, aragonite, and vaterite, and the magnesium carbonate is present in at least one form selected from neskehonite, magnesite, and hydromagnesite is doing,
Composition.   65. The composition of claim 64, wherein the calcium carbonate is present as olivine and the magnesium carbonate is present as neskehonite.   66. The composition of claim 65, wherein silica is 20% or less of the siliceous composition.   66. The composition of claim 65, wherein silica is 10% or less of the siliceous composition.   65. The composition of claim 64, wherein the silica particles are wholly or partially encapsulated with synthetic calcium carbonate or synthetic magnesium carbonate. a) a lime sanitizer adapted to sanitize metal oxide waste sources;
b) a precipitation reactor; and c) a liquid-solid separator;
Including
The precipitation reactor is operatively connected to both the lime slaker and the liquid-solid separator, and further such that the system produces carbonate-containing precipitation material in an amount exceeding 1 ton / day. Configured to,
system.   70. The system of claim 69, wherein the system is configured to produce carbonate-containing precipitated material in an amount greater than 10 tons / day.   70. The system of claim 69, wherein the system is configured to produce carbonate-containing precipitated material in an amount greater than 100 tons / day.   70. The system of claim 69, wherein the system is configured to produce carbonate-containing precipitated material in an amount greater than 1000 tons / day.   70. The system of claim 69, wherein the system is configured to produce carbonate-containing precipitated material in an amount greater than 10,000 tons / day.   70. The system of claim 69, wherein the lime slaker is selected from a slurry dwell lime slaker, a paste lime slaker, and a ball mill lime slaker.   70. The system of any of claims 69, further comprising a source of carbon dioxide.   66. The system of claim 65, wherein the source of carbon dioxide is from a coal-fired power plant or a cement plant.   70. The system of any of claims 69, further comprising a source of proton scavenger.   70. The system of any of claims 69, further comprising a source of divalent cations.   70. The system of any of claims 69, further comprising a building material generation unit configured to produce building material from the solid product of the liquid-solid separator.

Images