Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/18—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing mixtures of the silica-lime type
  • C04B28/186—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing mixtures of the silica-lime type containing formed Ca-silicates before the final hardening step
  • C04B28/188—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing mixtures of the silica-lime type containing formed Ca-silicates before the final hardening step the Ca-silicates being present in the starting mixture
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
  • B28B11/24—Apparatus or processes for treating or working the shaped or preshaped articles for curing, setting or hardening
  • B28B11/245—Curing concrete articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
  • B28B11/24—Apparatus or processes for treating or working the shaped or preshaped articles for curing, setting or hardening
  • B28B11/247—Controlling the humidity during curing, setting or hardening
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
  • C04B40/02—Selection of the hardening environment
  • C04B40/0231—Carbon dioxide hardening
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
  • Y02P40/18—Carbon capture and storage [CCS]

Definitions

• the invention relates to curing equipment in general and particularly to curing equipment that is used with materials that cure by reaction with CO2.
• the invention features an apparatus for curing materials that cure under reaction with CO2, comprising: a curing chamber configured to contain a material that consumes CO2 as a reagent, the material does not cure in the absence of CO2 during curing, the material does not cure in the presence of water alone, and the material does not consume water during curing, the curing chamber having at least one port configured to allow the material to be introduced into the curing chamber and to be removed from the curing chamber, and having at least one closure for the port, the closure configured to provide an atmospheric seal when closed so as to prevent contamination of a gas present in the curing chamber by gas outside the curing chamber; a source of carbon dioxide or air configured to provide gaseous carbon dioxide or air to the curing chamber by way of a gas entry port in the curing chamber, the source of carbon dioxide or air having at least one flow regulation device configured to control a flow rate of the gaseous carbon dioxide or air into the curing chamber; a gas flow subsystem configured to circulate the gaseous carbon dioxide or air
• the absolute pressure of the curing process executed in said chamber takes place at pressures in the range of 0.1 atmospheres to lower than 5 atmospheres absolute pressure in order to avoid the use of complex, pressure-rated components.
• the process takes place between 0.68 - 1.36 atmospheres (10-20 psi) absolute pressure. More preferably, the process takes place between 0.98 - 1.02 atmospheres (14.5-14.9 psi) absolute pressure.
• the apparatus is configured to first expose the material to the first drying phase (Phase 1) in absence of deliberately added C0 2 .
• the apparatus is configured to first expose the material to the first drying phase (Phase 1) in presence of CO2.
• the apparatus is configured to detect a transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in one or more electrical properties of the material on the surface or in the bulk thereof.
• the one or multiple electrical properties of the material include at least one of a surface resistivity, a volume resistivity, a conductivity, an impedance, a capacitance, a dielectric constant, a dielectric strength, a permittivity, a piezoelectric constant, and a Seebeck coefficient.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the quantity of water that is removed from the material.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the rate of water removed from the material.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the rate of water collected from the gas circulating in the chamber.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in at least one of a CO2 concentration and an O2 concentration in the gas circulating in the chamber.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the relative humidity of the gas circulating in the chamber. [0018] In one embodiment, the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in temperature of the gas circulating in the chamber.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in temperature of the material.
• the apparatus is configured to monitor the change in temperature of the material using an infrared camera.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the pressure inside the chamber.
• the apparatus is configured to measure, track and control the pressure inside the chamber throughout the process in any of the first drying phase (Phase 1) and the second curing phase (Phase 2).
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the pH of the material.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the pH of the water collected during curing of the material.
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the elemental composition of the material.
• the apparatus is configured to measure, track and control the elemental composition of the material throughout the process in any of the first drying phase (Phase 1) and the second carbonation phase (Phase 2).
• the apparatus is configured to detect the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) by detecting a change in the response of the material to ultrasonic stimulation.
• the temperature control subsystem further comprises at least one energy source configured to heat at least one of the gas and the material.
• the temperature control subsystem is configured to control the material temperature, a rate of water removal in the first drying phase (Phase 1) and a rate of reaction in the second carbonation phase (Phase 2).
• the energy source is configured to control the time of residence in at least one of the first drying phase (Phase 1) and the second carbonation phase (Phase 2).
• the energy source is configured to employ fossil fuel combustion.
• the energy source is configured to employ electrical resistance heating.
• the energy source is configured to employ an infrared heat source.
• the energy source is configured to employ a laser.
• the energy source is configured to employ dielectric heating.
• the energy source configured to employ dielectric heating uses microwave frequency waves or radio frequency waves.
• the energy source configured to employ dielectric heating uses radio frequencies in the Industrial, Science and Medical band (ISM band).
• ISM band Industrial, Science and Medical band
• the energy source is configured to employ plasma heating.
• the energy source is configured to employ steam heating.
• the energy source is configured to employ superheated steam.
• the energy source is configured to employ conduction.
• the energy source is configured to employ a radiator.
• the energy source is configured to employ a radiation heat source.
• the energy source is configured to employ a co-generation facility.
• the humidity control subsystem is configured to control the water extraction from the material.
• the humidity control subsystem is configured to control the water extraction from the gas in the chamber during at least one of the first drying phase (Phase 1) and the second carbonation phase (Phase 2).
• the humidity control subsystem is configured to control the water extraction using natural convection.
• the humidity control subsystem is configured to control the water extraction using forced convection.
• the humidity control subsystem is configured to control the water extraction using a compressor.
• the humidity control subsystem is configured to control the water extraction using a desiccant.
• the humidity control subsystem is configured to control the water extraction using one of a heat exchanger and a chiller.
• the humidity control subsystem is configured to control the water extraction using lower than atmospheric pressure.
• the gas flow subsystem is configured to control the circulation of the gas in the chamber to control the water removal in the first drying phase
• the gas flow subsystem is configured to control a flow and a velocity of the gas adjacent to the material.
• the gas flow subsystem is configured to control the circulation of the gas in the chamber to control the rate of reaction in the second carbonation phase (Phase 2).
• the gas flow subsystem is configured to control the flow and velocity of the gas using a plenum.
• the gas flow subsystem is configured to control the flow and velocity of the gas using an internal circulation system.
• the internal circulation system comprises a fan.
• the gas flow subsystem is configured to control the flow and velocity of the gas using an external circulation system.
• the extemal circulation system comprises a fan.
• the apparatus comprises an internal circulation system, an external circulation system and a bypass configured to proportion a gas flow between the internal circulation system and the extemal circulation system.
• the apparatus comprises multiple internal circulation systems, multiple extemal circulation systems, multiple heaters, and multiple dehumidification systems so as to comprise multiple independent control zones within the curing chamber.
• the gas flow regulation device is configured to change the concentration of C0 2 during the first drying phase (Phase 1) and second carbonation phase (Phase 2) to maximize the efficiency of CO 2 consumption during the curing process.
• the concentration of CO 2 is reduced during the second carbonation phase (Phase 2).
• the invention relates to a method of curing a material that consumes CO 2 as a reagent, the material does not cure in the absence of CO 2 during curing, the material does not cure in the presence of water alone, and the material does not consume water during curing, comprising the steps of: providing an apparatus comprising: a curing chamber configured to contain a material that consumes C0 2 as a reagent, the material does not cure in the absence of CO 2 during curing, the material does not cure in the presence of water alone, and the material does not consume water during curing, the curing chamber having at least one port configured to allow the material to be introduced into the curing chamber and to be removed from the curing chamber, and having at least one closure for the port, the closure configured to provide an atmospheric seal when closed so as to prevent contamination of a gas present in the curing chamber by gas outside the curing chamber; a source of carbon dioxide or air configured to provide gaseous carbon dioxide or air to the curing chamber by way of a gas entry port in the
• the invention relates to an apparatus for curing of materials that harden under reaction with CO 2 and that do not harden in the presence of water alone, comprising: a curing chamber configured to contain a material that consumes CO 2 as a reagent and that does appreciably harden in the absence of CO 2 , said curing chamber having at least one port configured to allow said material to be introduced into said curing chamber and to be removed from said curing chamber, and having at least one closure for said port, said closure configured to provide an atmospheric seal when closed so as to prevent contamination of a gas present in said curing chamber by gas outside said curing chamber; a source of carbon dioxide or air configured to provide gaseous carbon dioxide or air to said curing chamber by way of a gas entry port in said curing chamber, said source of carbon dioxide or air having at least one flow regulation device configured to control a flow rate of said gaseous carbon dioxide or air into said curing chamber; a gas circulation subsystem configured to circulate said gas through said curing chamber at a controlled flow rate and velocity
• the invention relates to a method of curing materials that harden under reaction with CO 2 and that do not harden in the presence of water alone, comprising the steps of: performing a first drying phase (Phase 1) having a reduced time of residence in said first drying phase (Phase 1), and performing a second carbonation phase (Phase 2) at the end of said first drying phase (Phase 2).
• the invention in another aspect, relates to a method of curing materials that harden under reaction with CO 2 and that do not harden in the presence of water alone, comprising the steps of: performing a first drying phase (Phase 1) having a reduced time of residence in said first drying phase (Phase 1), performing a second carbonation phase (Phase 2) at the end of said first drying phase (Phase 2), and repeating said first drying phase (Phase 1) and second carbonation phase (Phase 2) at least once.
• the invention relates to a method of curing materials that harden under reaction with CO 2 and that do not harden in the presence of water alone, comprising the steps of: performing a first drying phase (Phase 1) having a reduced time of residence in said first drying phase (Phase 1), performing a second carbonation phase (Phase 2) at the end of said first drying phase (Phase 1), and repeating said first drying phase (Phase 1) and second carbonation phase (Phase 2) more than once.
• the invention relates to a method of curing materials that harden under reaction with CO 2 and that do not harden in the presence of water alone, comprises of removing the balance moisture in the product as a part of any of the second carbonation phases (Phase 2).
• the removing of the balance moisture in the product comprises of any of the first drying phase (Phase 1).
• FIG. 1C to be analyzed by the curing system to control the velocity, temperature, and humidity of the gas stream local to the products, and thus evaporation rate, in order to remove the quantity of water specified and create or maintain the distribution of moisture in the pore structure of the product as specified during any of the drying phases (Phase 1) and/or any of the carbonation phases (Phase 2).
• FIG. 1C to be analyzed by the curing system to control the velocity, temperature, and humidity of the gas stream local to the products in fixed zones throughout the chamber during any of the drying phases (Phase 1) and/or carbonation phases (Phase 2) according to the state of the products and system in order to unify the level of dryness throughout the chamber.
• Phase 1 drying phases
• Phase 2 carbonation phases
• FIG. 1C to be analyzed by the curing system to control the velocity, temperature, and humidity of the gas stream local to the products in the entire chamber during the any of the drying phases (Phase 1) and/or the carbonation phases (Phase 2) according to the state of the products and system.
• FIG. 1C to be analyzed by the curing system to control the CO2 concentration of the circulating gas during any of the drying phases (Phase 1) and/or the carbonation phases (Phase 2) according to the state of products and system.
• FIG. 1 A is a schematic diagram that illustrates exemplary embodiments of advanced curing equipment according to principles of the invention.
• Phase I 150
• Phase II 160
• FIG. IB is a schematic diagram that illustrates exemplary embodiments of chambers used in advanced curing equipment according to principles of the invention.
• FIG. 1C is a schematic diagram that illustrates exemplary embodiments of sensors used in advanced curing equipment according to principles of the invention.
• FIG. ID is a schematic diagram that illustrates exemplary embodiments of a first processing phase practiced using advanced curing equipment according to principles of the invention.
• FIG. IE is a schematic diagram that illustrates exemplary embodiments of a second processing phase practiced using advanced curing equipment according to principles of the invention.
• FIG. IF is a schematic diagram that illustrates exemplary embodiments of parameters that are measured that relate to the chamber characteristics of chambers and exemplary embodiments of material parameters that are measured during processing in advanced curing equipment according to principles of the invention.
• FIG. 1G is a schematic diagram that illustrates exemplary embodiments of process control components of the apparatus according to principles of the invention.
• FIG. 2 is a schematic graph that illustrates the mass of a CO 2 Composite
• CCM Material that is being cured as a function of time during CC ⁇ -curing.
• FIG. 3 shows the mass and CO2 uptake of a sample during curing which illustrates the separate Phase 1 drying and Phase 2 carbonation.
• FIG. 3 is a diagram illustrating data for curing Example 1.
• FIG. 4A illustrates the sample temperature and RH profile during phase I drying in curing Example 2.
• FIG. 4B illustrates the sample temperature and RH profile during phase II carbonation in curing Example 2.
• FIG. 4C illustrates the sample temperature and RH profile during phase III carbonation in curing Example 2.
• FIG. 5A is a graph illustrating a system curing profile in curing Example 3.
• FIG. 5B is a graph illustrating a system curing profile in curing Example 3.
• FIG. 5C is a graph illustrating sample surface resistance data and system curing profiles for curing Example 3.
• FIG. 6 is a graph that illustrates the differences in reaction depth, gas flow in cubic feet per minute and amount of water removed from specimens of CO2 Composite Material cured in systems using 1 fan and 3 fans.
• FIG. 7 is a graph showing data for water removal rate as a function of flow rate for gases having different relative humidity.
• FIG. 8 is a graph showing the calculated temperature behavior with time for drying alone and for carbonation alone, obtained by de-convolution.
• Figs. 9 through 12 are part of the prior art description found in U.S. Patent
• FIG. 9 represents g-rHLPD process Schematic.
• A Dropried porous CaSiCb preform; B ⁇ Partially wet CaSiCb preform; C ⁇ Final densified monolithic solid.
• Steps 1 to 4 represent the carbonation-densification process occurring in an individual pore: Step 1- Partially wet pore with CO2; Step 2 ⁇ Diffusion, dissolution and dissociation of CO2; Step 3— Dissolution of CaSiC ⁇ by hydrogen ions; Step 4 ⁇ Precipitation of solids. After the completion of step 4, the process takes place continuously following steps 2-4 until various kinetic factors slow down the process (e.g., thick CO2 reaction layers).
• FIG. 10 represents a first example of carbonation reactions involving CO2 as a gas phase and liquid water in the pore structure.
• FIG. 11 represents a second example of carbonation reactions involving CO2 as a gas phase and liquid water in the pore structure: Carmel Quartz Composition, 8 x 8 x 1.5" Vibratory Cast reacted, 90 C, 20 PSIG reaction.
• FIG. 12 represents a third example of carbonation reactions involving CC ⁇ as a gas phase and liquid water in the pore structure: 1-2-3 Composition, 8 x 8 x 2" sample size reacted at 90 C 20 PSIG, at -90% Relative humidity.
• the apparatus, methods and systems of the invention are useful for curing materials that require CO2 for curing.
• the materials do not cure in the presence of H 2 0 alone.
• the materials do not cure in the absence of CO2.
• the materials do not consume water as a reagent.
• Such materials are described in the patent documents that are incorporated by reference herein.
• the invention features a curing system for curing a material which requires CO2 as a curing reagent.
• the curing system comprises a curing chamber configured to contain a material that consumes CO2 as a reactant (or reagent) and that does not cure in the absence of CO2.
• the curing chamber has at least one port configured to allow the material to be introduced into the curing chamber and to be removed from the curing chamber, and has at least one closure for the port, the closure configured to provide an atmospheric seal when closed so as to prevent (or to limit to an innocuous level) contamination of a gas present in the curing chamber by gas outside the curing chamber; a source of carbon dioxide configured to provide gaseous carbon dioxide to the curing chamber by way of a gas entry port in the curing chamber, the source of carbon dioxide having at least one flow regulation device configured to control a flow rate of the gaseous carbon dioxide into the curing chamber; a gas flow subsystem configured to circulate the gas through the curing chamber during a time period when the material that consumes CO2 as a reactant is being cured; a temperature control subsystem configured to control a temperature of the gas within the chamber; a humidity control subsystem configured to control a humidity in the gas within the chamber to increase or decrease humidity; and at least one controller in communication with at least one of the source of carbon dioxide, the gas
• the invention involves the recognition that the drying sub-process and the carbonation sub-process in the curing of CO2 composite material are directly coupled to each other, so that the carbonation rate and extent can be controlled by controlling the drying rate.
• the absolute pressure of the curing process executed in said chamber takes place at fewer than 5 atmospheres in order to avoid the use of complex, pressure-rated components.
• the process takes place between 0.68 - 1.36 atmospheres (10-20 psi) absolute pressure. More preferably, the process takes place between 0.98 - 1.02 atmospheres (14.5-14.9 psi) absolute pressure.
• portions of the process may proceed at less than atmospheric pressure in order to facilitate the evaporation of water from the products to be cured.
• the invention contemplates a process that maximizes the carbonation rate of a composite material by controlling the drying rate of that material.
• the process can include a carbonation duration that is between 0 and 1,000 hours.
• the process can include a CO2
• Composite Material that has a permeability in the range of 0% to 100%.
• the permeability within the range of 0% to 100% can have an upper bound or a lower bound of a respective one of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%,50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%.
• the process can include a CO2 Composite Material that has a carbonation depth of the CCM in the range of 0 and 36 inches.
• the process can include a CO2 Composite Material wherein the amount of water removed from the CCM is equal to between 0% and 99% of the CCM mass. In some embodiments, the amount of water removal is in the range of 10-90%, 15-90%, 20-90%, 25-90%, 30-90%, 35-90%, 40-90%, 45-90%, or 50-90% of the CCM mass.
• the amount of water removal is in the range of 10-85%
• the amount of water removal is in the range of 10-80%
• the amount of water removal is in the range of 10-75%
• the amount of water removal is in the range of 10-70%
• the amount of water removal is in the range of 10-65%
• a curing process for carbonatable calcium silicate concretes is defined as a process wherein concrete products are produced using carbonatable calcium silicate cements and exposed to CO2 in a controlled manner to produce a cured concrete part with desirable physical and/or chemical properties.
• Concrete products containing carbonatable calcium silicate cements as their primary cementitious binding agent harden during the reaction process.
• Monitoring the mass and C0 2 consumption of a concrete body during the curing process reveals two distinctive phases during curing. This is demonstrated in FIG. 2.
• the first phase is a drying phase, where minimal or no consumption of CO2 occurs but the mass of the product decreases as water is evaporated from the product to the chamber atmosphere.
• the second phase is a carbonation phase, where the rate of CO2 consumption increases and the mass gain from carbonation exceeds the mass loss from drying.
• the rate of CO2 consumption and subsequent mass gain of the solid decreases as the carbonation reaction process approaches its maximum yield for the specific product and conditions employed in the curing process.
• the curing process is comprised of two distinct phases, a drying phase (Phase 1) and a carbonation phase (Phase 2).
• the vertical axis is labeled Mass.
• the units used to designate mass for the sample mass which includes water as well as the solid substances in the sample (designated by a solid curve) and the accumulated CO2 mass (designated by a dotted curve) can have different scales. That is, the addition of CO2 to a material to be cured in general represents a significantly smaller absolute mass than the mass of the material to be cured, because CO2 has a molecular weight of approximately 44 atomic units, while most solids comprise multiple chemical elements such as Ca, Mg and Si that individually have atomic masses of approximately 40, 24 and 28 atomic units, respectively.
• Phase 1 and Phase 2 may vary depending on product formulation, the concrete raw materials, the properties of the cement and binder components, the product density, the product geometry, the use of chemical additives, and the conditions applied during the curing process.
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the electrical properties of the product on the surface or in the bulk. In some embodiments, one or multiple electrical properties, such as, the resistivity, conductivity, impedance, capacitance, dielectric constant, dielectric strength, permittivity, piezoelectric constant, Seebeck coefficient of the product may change.
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the quantity of water is removed from the product. In some embodiments, the quantity of water removed from the product is measured through tracking the mass change of the product throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the rate of water removed from the product.
• the rate at which water extracted from the product is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the rate of water collected from the gas circulating in the chamber.
• the rate at which water is collected from the gas circulating in the chamber is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the CO2 and/or O2 concentration in the gas circulating in the chamber.
• the CO2 and/or O2 concentration of the gas circulating in the chamber is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the relative humidity of the gas circulating in the chamber.
• the relative humidity of the gas circulating in the chamber is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in temperature of the gas circulating in the chamber.
• the temperature of the gas circulating in the chamber is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in temperature of the gas circulating in the chamber.
• the temperature of the gas circulating in the chamber is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in temperature of the product.
• the temperature of the product is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the change in temperature of the product is monitored using an infrared camera.
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the pressure inside the chamber.
• the pressure inside the chamber is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second curing phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the pH of the product.
• the pH of the product is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the pH of the water collected during the process from the products and subsequently from the chamber.
• the pH of the water collected during the process from the products and subsequently from the chamber is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the elemental composition of the product.
• the elemental composition of the product is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• the transition from the first drying phase (Phase 1) to the second carbonation phase (Phase 2) is associated with a change in the response of the product to ultrasonic stimulation.
• the response of the product to ultrasonic stimulation is measured, tracked and controlled throughout the process in any of the first drying phases (Phase 1) or any of the second carbonation phases (Phase 2).
• control of product temperature and water removal in the first drying phase (Phase 1) and the rate of reaction in the second carbonation phase (Phase 2) is controlled, and in some instances expedited, through selection of an energy source.
• the energy source used for heating the gas and/or the product is fossil fuel combustion.
• the energy source used for heating the gas and/or the product is electrical resistance heating.
• the energy source used for heating the gas and/or the product is an infrared heat source.
• the energy source used for heating the gas and/or the product is a laser.
• the energy source used for heating the gas and/or the product is dielectric heating, wherein dielectric heating may employ the use of waves of microwave frequency or radio frequency.
• the radio frequencies used is in the Industrial, Science and Medical band (ISM band).
• the energy source used for heating the gas and/or the product is plasma.
• the energy source used for heating the gas and/or the product is steam.
• the energy source used for heating the gas and/or the product is superheated steam.
• the energy source used for heating the gas and/or the product is conduction.
• the energy source used for heating the gas and/or the product is a radiator.
• the energy source used for heating the gas and/or the product is a radiation heat source.
• the energy source used for heating the gas and/or the product is a heat source such as co-generation facility.
• the energy source used for heating the gas and/or the product includes a combination of the heat sources described above.
• control of the water removal in the first drying phase (Phase 1) and/or the rate of reaction in the second carbonation phase (Phase 2) is controlled, and in some instances expedited, through control of the water extraction from the product and subsequently from the gas in the chamber.
• the water extraction from the product and subsequently from the chamber is controlled through natural convection.
• the water extraction from the product and subsequently from the chamber is controlled through forced convection.
• the water extraction from the product and subsequently from the chamber is controlled through a compressor.
• the water extraction from the product and subsequently from the chamber is controlled through a desiccant.
• the water extraction from the product and subsequently from the chamber is controlled through a heat exchanger/chiller.
• the water extraction from the product and subsequently from the chamber is controlled through the use of lower than atmospheric pressure regimes including but not limited to vacuum.
• the water extraction from the product and subsequently from the chamber is controlled through the use of a combination of processes described above.
• the control of the water removal in the first drying phase (Phase 1) and/or the rate of reaction in the second carbonation phase (Phase 2) is controlled, and in some instances expedited, through control of the circulation of the gas in the chamber.
• the velocity of the gas local to the products is controlled through adjusting the flow of the gas in the chamber.
• the flow of the gas is controlled using an engineered plenum.
• the flow of the gas and the velocity of gas over the products are controlled using an internal circulation system.
• the engineered internal circulation inside the chamber comprises of fans that move the gas inside the chamber.
• the flow of the gas is controlled using an external circulation system.
• the engineered external circulation system comprises of fans that move the gas between the interior and exterior of the chamber.
• the flow of the gas is controlled using an internal circulation system and an extemal circulation system in tandem.
• the flow of gas is proportioned between the internal circulation system and the extemal circulation system by means of a bypass.
• a curing system comprises multiple internal circulation systems, external circulation systems, heaters, and dehumidification systems may be affixed to one chamber providing multiple independent control zones within the chamber.
• the efficiency of CO 2 consumption during the curing process is maximized by adjusting the CO 2 concentration at the end of the carbonation phase (Phase 2) and/or the final drying phase. More specifically, the CO 2 concentration is allowed to drop in the chamber during the carbonation phases as the CO 2 uptake rate by the product decreases. This assists with the conservation of the CO 2 , which is essential from both a cost and an environmental consideration.
• a curing chamber was loaded with carbonatable calcium silicate cement concrete pavers. Previous measurements indicated a distribution of relative evaporation rates throughout the chamber. Electrical resistance sensors were placed on the surfaces of products at locations known to have relatively high and relatively low evaporation rates.
• the curing process commenced by introducing CO2 to the chamber and gas conditioning system until a high concentration was reached. Next, flow, heat, and system dehumidification were adjusted to reach a desired temperature and relative humidity. The chamber reached 60°C in 2.5 hours and the relative humidity was maintained at or below 60%.
• Carbonatable calcium silicate cement based concrete cylinders were produced to study a curing process including phase 1 drying in the absence of CO2.
• the mixture proportions used for production of fresh concrete is shown in Table 1.
• the fresh properties of concrete produced using the materials as per quantities in Table 1 are shown in Table 2.
• Table 1 The mixture proportions of the concrete produced for Example 2.
• Table 2 The fresh properties of the concrete produced for Example 2.
• ABS mold containing the wet cast specimen was loaded into a curing chamber. Two curing processes were investigated. The duration of each investigated curing process was 14 hours.
• the curing recipe was modified so that the evaporation rate of the sample was reduced during the carbonation phase in order to enhance the extent of the carbonation curing.
• the curing chamber was purged to achieve a high CO2 concentration (>90%).
• the heater and gas circulation system were controlled to achieve a temperature of 60°C and a relative humidity of 25% or lower.
• the gas circulation settings were modified to create a high humidity in the chamber and thus reduce the evaporation rate for three hours.
• the gas circulation system settings were modified to gradually increase the evaporation rate by capping the chamber relative humidity at 50% for two hours.
• the gas circulation system and heater settings were modified to increase the gas temperature 70°C and cap the chamber relative humidity at 25% for the remainder of the run.
• FIG. 5C The chamber temperature, chamber relative humidity, and the electrical resistance of the sample surface for curing process A and curing process B are illustrated in FIG. 5C.
• the internal paver temperature reached 60°C in 1 minute and 85°C in 2 minutes.
• Carbonatable calcium silicate cement based pavers can be heated and dried using Radio Frequency and then cured in a CO2 environment without the use of Radio Frequency. Using Radio Frequency only during the first heat-up and drying phase of the process can still reduce the total process time significantly. Re-wetting of the surface appeared to be beneficial after a very rapid heat up phase.
• FIG. 6 is a graph that illustrates the differences in reaction depth, gas flow in cubic feet per minute and amount of water removed from specimens of CO2 Composite Material cured in systems using 1 fan and 3 fans. It is apparent that reaction depth, gas flow in cubic feet per minute and amount of water removed from specimens of CO2 Composite Material all increase when more capacity to move the reactive gas is provided.
• FIG. 7 is a graph showing data for water removal rate as a function of flow rate for gases having different relative humidity. As is seen in FIG. 7, using a higher flow rate and a lower relative humidity tends to increase the rate at which water is removed from the sample. It is believed that the reaction of CCM with CO2 occurs preferentially at the interface where water-saturated CCM is in contact with gaseous CO2, so more rapid removal of water correlates with faster rates of cure.
• FIG. 8 is a graph showing the calculated temperature behavior with time for drying alone and for carbonation alone, obtained by de-convolution, as explained in USSN 14/602,313, which has been incorporated by reference herein.
• FIG. 8 includes a comparison of the carbonation exotherm with the drying endotherm plotted on the same time scale.
• FIG. 8 indicates that drying can be used to control reaction speed and extent.
• a drying front establishes itself and moves from the outside of the formed object toward its interior.
• a reaction front also forms almost coincident with the drying front.
• the curing reaction can only occur near the drying front/reaction front because CO2 is supplied as a gas and is not present initially in the water at any significant concentration.
• CO2 is supplied as a gas and is not present initially in the water at any significant concentration.
• front of the drying front e.g., on the wet side of the front
• water is present in the pores, which inhibits CO2 diffusion.
• Behind the front e.g., on the dry side of the front
• the pores contain too little water to support carbonation, but CO2 can diffuse quickly to the region of the front and water can diffuse from the front back to the surface of the formed body.
• the extent of reaction will be lower than if the fronts move slowly compared to the intrinsic rate of chemical reaction.
• the shape of the drying front will depend on the external shape of the formed body, the relative drying rates through its external surfaces and the diffusion distances from the front to the surface of the formed body.
• diffusional processes rate-limit a process when the thickness through which diffusion must occur is greater than the diffusion distance, which can be estimated by computation of root mean square displacement. For example, for a fluid with no convection, the diffusion of ions at room temperature and atmospheric pressure in water is approximately 0.19 cm. There are many applications where thicknesses of materials exceed this length scale. In these cases, mechanical convection of the fluid by any suitable means known to one of skill in the art is necessary. Another alternative is to introduce the solvent or reactive species as a gaseous species. When this is done, the diffusion distance increases to 9 cm. In further embodiments, supercritical conditions can be employed to achieve transport rates that lie between liquids and gases.
• FIG. 9 represents g-rHLPD process Schematic.
• A Dropried porous CaSiCb preform; B ⁇ Partially wet CaSiC ⁇ preform; C ⁇ Final densified monolithic solid.
• Steps 1 to 4 represent the carbonation-densification process occurring in an individual pore: Step 1- Partially wet pore with CO2; Step 2 ⁇ Diffusion, dissolution and dissociation of CO2; Step 3— Dissolution of CaSiCb by hydrogen ions; Step 4 ⁇ Precipitation of solids. After the completion of step 4, the process takes place continuously following steps 2-4 until various kinetic factors slow down the process (e.g., thick CO2 reaction layers).
• rHLPD gas-assisted hydrothermal liquid phase densification
• g-rHLPD utilizes partially infiltrated pore space so as to enable gaseous diffusion to rapidly infiltrate the porous preform and saturate thin liquid interfacial solvent films in the pores with dissolved CO2.
• CC ⁇ -based species have low solubility in pure water (1.5 g/L at 25° C, 1 atm). Thus, a substantial quantity of CO2 must be continuously supplied to and distributed throughout the porous preform to enable significant carbonate conversion.
• Utilizing gas phase diffusion offers a 100-fold increase in diffusion length over that of diffusing soluble CO2 an equivalent time in a liquid phase.
• This partially infiltrated state enables the reaction to proceed to a high degree of carbonation in a fixed period of time.
• 47.5 ⁇ 2.7 mol % conversion of CaSiCb into CaCCb and S1O2 can be achieved in -19 h at a temperature of 90° C. and a pressure of 2.36 atm. If all the same reaction conditions are maintained except that the pores are completely filled with water, a substantially lower carbonation conversion, 3.8 ⁇ 0.5 mol %, results.
• the porous matrix redistributes the water in the matrix homogenously using capillary flow with no mass loss.
• the degree of carbonation varies from 31.3 mol % to a maximum level of 49.6 mol % beyond this value, the degree of carbonation drops to 35.6 mol % when the DPS is increased to 80% and to 3.8 mol % when the DPS is 100%.
• infiltrate solution levels need to be low enough such that CO2 gas can diffuse into the porous matrix by gaseous diffusion prior to dissolution and diffusion in the pore-bound in water phase to the porous matrix solid/liquid interface. This is all schematically shown in FIG. 9.
• the particle size distribution is monodisperse, while in many practical cases the particle size is poly disperse and the packing of the particles could adopt a wide variety of configurations that include hierarchic structures where the packing configurations repeat at each hierarchic level or change at each level. It is also conceivable that the packing structure can have long-range order, short-range order or adopt a random level of order at every length scale, whether the length scale is small, medium or large. Alternatively, short-range order may only persist on small length scale and random on the medium and large length scales. It is also possible that particles can pack with random order scale on the short length scale but then these regions of random order could be periodically distributed on the large length scale.
• the packing density can vary from a small value that could be as high as 99 vol % with ordered hierarchic packing that repeats at large, medium and small length scales.
• the packing density could be as low as 0.04 vol % when the packing structure is characteristic of an aerogel, with fractal or dendritic packing in of particle or inorganic polymer in the porous matrix.
• the amount of water required to saturate the pores with 99 vol % packing is a very small amount of water while the amount required to saturate pores with 0.04 vol % is a very large amount.
• the requirement is to maintain open porosity to enable a rapid reaction between the gas phase and the water and the water and the solid phase, then it is conceivable to one of ordinary skill that the optimum amount of water to enable a fast reaction will be different for each system.
• the amount of water required is also dependent on the sizes of the pores, shapes of the pores, the tortuosity of the pores and whether any of the pores happen to be closed pores. Closed pores will not provide reactive sites for the infiltrating solution unless it is transformed to an open pore by the ensuing reaction that dissolves significant portions of the porous matrix.
• the above discussion assumes the porous structure is uniform. However, if the pore structure is not uniform, then the optimum concentration of the water depends on the region of heterogeneous structure being saturated with water. That being said, considering a system that has
• an important aspect of this invention is the recognition that the optimum water concentration can in fact vary over a very wide range of water concentration whenever it is important for a gas to convect or diffuse into a pore structure, dissolve and react with the solvent and subsequently react with the porous matrix.
• Another important point of this invention is to recognize that there are different ways to distribute water in the porous matrix, as mentioned in this specification. For instance, if a fully saturated porous compact is saturated with water, drying could be used to create open pores. However, the pores in this structure have different DPS values as you travel from the outer surface to the inner bulk of the porous matrix. In the outer surface, pores will contain no water but as you move inward into the structure, pores are partially filled and as you move further into the structure the pores are completely filled. This structure clearly has a large gradient in DPS value and thus, the rate of reaction in this structure will vary from the outside of the structure towards the inside of the structure, assuming the gradient DPS structure remains static.
• the drying step is immediately ceased and the relative humidity is adjusted to the equilibrium value such that water loss from the porous matrix ceases, capillarity will drive the filled pores to empty into the partially filled ones and the partially filled pores will partially fill the empty pores where the entire structure will have a much more uniform distribution of water.
• the non-uniform system will not react as fast as the uniform one because more reaction sites are available in the uniform one due to all the pores being accessible.
• this example shows how the distribution of water in the porous matrix is equally important.
• the optimum concentration of water also depends on whether the porous structure is maintained as homogeneous or inhomogeneous.
• FIGS. 10-12 are three examples of how carbonation reactions involving CO2 as a gas phase and liquid water in the pore structure exhibit an optimum DPS value to maximize the degree of carbonation of a given CaSiC ⁇ binder.
• g-rHLPD utilizes partially infiltrated pore space so as to enable gaseous diffusion to rapidly infiltrate the porous preform and saturate thin liquid interfacial solvent films in the pores with dissolved CO2.
• CC ⁇ -based species have low solubility in pure water (1.5 g/L at 25° C, 1 atm).
• a substantial quantity of CO2 must be continuously supplied to and distributed throughout the porous preform to enable significant carbonate conversion.
• Utilizing gas phase diffusion offers a 100-fold increase in diffusion length over that of diffusing soluble CO. sub.2 an equivalent time in a liquid phase.
• the reaction can proceed to a high degree of carbonation in a fixed period of time.
• 47.5 ⁇ 2.7 mol % conversion of CaSiC ⁇ into CaCCb and S1O2 can be achieved in -19 h at a temperature of 90° C. and a pressure of 2.36 atm. If all the same reaction conditions are maintained except that the pores are completely filled with water, a substantially lower carbonation conversion, 3.8 ⁇ 0.5 mol %, results.
• the porous matrix redistributes the water in the matrix homogenously using capillary flow with no mass loss.
• a porous matrix was prepared having a bulk density of 1.83-1.86 g/cc using the wet pressing method.
• the degree of carbonation varies from 31.3 mol % to a maximum level of 49.6 mol % beyond this value, the degree of carbonation drops to 35.6 mol % when the DPS is increased to 80% and to 3.8 mol % when the DPS is 100%.
• FIG. 10 represents a first example of carbonation reactions involving CO2 as a gas phase and liquid water in the pore structure.
• FIG. 11 represents a second example of carbonation reactions involving CO2 as a gas phase and liquid water in the pore structure: Carmel Quartz Composition, 8 x 8 x 1.5" Vibratory Cast reacted, 90 C, 20 PSIG reaction.
• FIG. 12 represents a third example of carbonation reactions involving CC ⁇ as a gas phase and liquid water in the pore structure: 1-2-3 Composition, 8 x 8 x 2" sample size reacted at 90 C 20 PSIG, at -90% Relative humidity (-90% RH).
• this range of value can be even greater, assuming the pore size and tortuosity is the same. If pore size and tortuosity were different, the value may vary over an even wider range.
• a key step in optimizing the degree of carbonation and carbonation rate is to recognize that there is an optimum DPS value for any given method of water delivery. Knowing this value will enable the determination of the ideal conditions for minimizing the amount of reaction time as well as crystallize more binding phase by the hydrothermal liquid phase sintering reaction.
• a further improvement of the invention can be made when gas species are mechanically convected by applying a pressure gradient across the porous matrix. If the gas is a reactive species, pores filled with solvent fluid can flow out of the pores leaving behind a film of solvent on the pores that can absorb the reactive species gas. Alternatively, partially filled pores will allow gas to flow through the pores as the solvent absorbs a portion of the gas flowing through.
• the preferred approach should utilize low temperatures and low pressures to enable low cost processes to be developed. Thus, processes that retain a fraction of solvent in the pores to facilitate gaseous diffusion of reactive species are preferred over those that utilize quiescent fluids for reactions where a large fraction of product is desired. If gaseous precursors are not available, then methods that mechanically convect the infiltration fluid rapidly through the porous matrix are a viable alternative approach.
• the mixer was run for an additional 1 minute and then the remaining batch water was added directly into the mix while the mixer was running. Then the batch was mixed for 2 minutes and the mixer was stopped. The sides of the mixer were scraped with a putty knife to remove stuck material. The mixer was started again and run at full speed for an additional 3 minutes. The mixer was stopped and mix poured into 5 gallon buckets.
• the autoclave used for curing (reacting) the samples is a stainless steel, horizontal, indirect steam unit with a radius of 7 and a length of 12 feet. Samples were loaded into the pre-heated autoclave at 90° C. After the autoclave door was closed, it was evacuated down to -14 psig in 15 minutes. The autoclave was back filled with heated C0 2 gas and steam at 147.5° C. to provide additional heat to the samples and to account for the heat loss occurred during sample loading and expansion of the gasses. Once the pressure in the autoclave reached 0 psig, the fan of the autoclave was started at 4900 RPM. The CO2 was cut off when the total pressure reached 10 psig. The autoclave temperature was set to 90° C.
• the autoclave used for curing the samples is a stainless steel, horizontal, indirect steam unit with a radius of 7 and a length of 12 feet. Samples were loaded in to the pre-heated autoclave at 90° C. After the autoclave door was closed the autoclave was back filled with heated CO2 gas and steam at 147.5° C. to provide additional heat to the samples and to account for the heat loss occurred during sample loading and expansion of the gasses.
• the fan of the autoclave was started at 4900 RPM.
• the CO2 was cut off when the total pressure reached 10 psig.
• the autoclave temperature was set to 90° C. and hot water at 95° C. was circulated at the bottom of the autoclave to keep the unit saturated with water vapor.
• the system was allowed to equilibrate for 45 min to 1 hr (total psi reaching approximately 16 psig), and then the autoclave pressure was increased to 20 psig by filling with heated CO2 gas only. The samples were cured for 19 hours.
• the mechanically convection comprises one of pressurized flow, capillary electro-osmotic flow, magneto-osmotic flow, and temperature- and chemical-gradient driven flow.
• the monolithic ceramic body has a degree of pore saturation value of from about 15% to about 70%.
• the signal is a non- transitory electronic signal or a non-transitory electromagnetic signal. If the signal per se is not claimed, the reference may in some instances be to a description of a propagating or transitory electronic signal or electromagnetic signal.

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