CA2443222C - A process and a plant for the production of portland cement clinker - Google Patents
A process and a plant for the production of portland cement clinker Download PDFInfo
- Publication number
- CA2443222C CA2443222C CA002443222A CA2443222A CA2443222C CA 2443222 C CA2443222 C CA 2443222C CA 002443222 A CA002443222 A CA 002443222A CA 2443222 A CA2443222 A CA 2443222A CA 2443222 C CA2443222 C CA 2443222C
- Authority
- CA
- Canada
- Prior art keywords
- ions
- exhaust gas
- cement
- kiln
- hydration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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
- C04B7/00—Hydraulic cements
- C04B7/36—Manufacture of hydraulic cements in general
- C04B7/364—Avoiding environmental pollution during cement-manufacturing
- C04B7/367—Avoiding or minimising carbon dioxide emissions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/62—Carbon oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/50—Carbon oxides
- B01D2257/504—Carbon dioxide
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/84—Biological processes
-
- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
-
- 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
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
-
- 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
- Y02P40/121—Energy efficiency measures, e.g. improving or optimising the production methods
-
- 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]
Abstract
A process is disclosed for producing cement clinker, comprising the steps of : a) providing a mixture of ground calcareous materials and ground argillaceou s materials; b) heating the mixture of step a) to a temperature sufficient to calcine and fuse the ground materials to form the cement clinker, and thereb y producing an exhaust gas containing CO2; c) catalysing the hydration of at least a portion of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate ions and hydrogen ions; and d) adding to the solution obtained in step c) metal ions, and adjusting the pH of the solutio n to precipitate a carbonate of said metal. Preferably, the metal ions are Ca+ + obtained from the dissolution of a material selected from the group consisti ng of CaCl2, cement kiln dust and sea salts and the carbonate is CaCO3 which is advantageously recycled into the process by adding the CaCO3 to the mixture of step a). A cement plant for performing this process is also disclosed.</SDOA B>
Description
A PROCESS AND A PLANT FOR THE PRODUCTION OF PORTLAND
CEMENT CLINKER
FIELD OF THE INVENTION
The present invention relates generally to the field of processes and apparatuses for the production of Portland cement clinker. More specifically, it concerns a.
process and a plant for the recovery and recycling of the carbon dioxide emissions from the production of Portland cement clinker.
BACKGROUND
Preserving the environment goes above all through the recognition of polluting lo agents, a list stretching out every year. Carbon dioxide is a by-product of many industrial chemical reactions and is considered polluting only of late. Until recently still, it was rather seen as a consequence of no gravity from the combustion of carbonated compounds such as coal and petroleum, or else, as a desired final product in the control of gaseous emissions.
is Accumulation of evidences as to the participation of COZ in the greenhouse effect responsible for earth's global warming revealed a problematic of extreme urgency.
On this account, international engagements proposed in Kyoto (Kyoto protocol, 1997) have commanded for active research in reducing greenhouse effect gases, particularly CO2.
CEMENT CLINKER
FIELD OF THE INVENTION
The present invention relates generally to the field of processes and apparatuses for the production of Portland cement clinker. More specifically, it concerns a.
process and a plant for the recovery and recycling of the carbon dioxide emissions from the production of Portland cement clinker.
BACKGROUND
Preserving the environment goes above all through the recognition of polluting lo agents, a list stretching out every year. Carbon dioxide is a by-product of many industrial chemical reactions and is considered polluting only of late. Until recently still, it was rather seen as a consequence of no gravity from the combustion of carbonated compounds such as coal and petroleum, or else, as a desired final product in the control of gaseous emissions.
is Accumulation of evidences as to the participation of COZ in the greenhouse effect responsible for earth's global warming revealed a problematic of extreme urgency.
On this account, international engagements proposed in Kyoto (Kyoto protocol, 1997) have commanded for active research in reducing greenhouse effect gases, particularly CO2.
2 o Amongst the finger pointed industries, cement fabrics account for 8 % of the CO2 planetary anthropic emissions. Portland cement is made of lime, alumina, iron and silica. This mixture is pulverized and fused together by burning at high heat (more than 1,400 C) in a rotary kiln. Combining the resulting material, called "clinker", with gypsum, results in the production of a fine powder known as Portland cement.
In the 25 production process, carbon dioxide emissions come from fossil fuel combustion and a calcination stage of limestone (CaCO3).
Portland cement is the binding agent that enables the formation of concrete, which will also include aggregates, air and water.
Portland cement is the result of a chemical combination of calcium (usually from limestone), silica (clay, sand and shale), alumina (bauxite), iron (ore) and small amounts of various chemicals called admixtures to which gypsum is added at the last grinding in order to control the cement setting process.
The production of one tonne of cement (2000) requires close to 3 500 tonnes of raw materials. Lime and silica account for approximately 85 % of the weight.
Two main categories of production processes are in use in this industry : the dry 1 o process kiln (70 % in the U.S.) and the wet process kiln (older). For both processes, the first step is similar. The raw materials are crushed for reduction to about 3 inches or smaller. In the wet process, the raw materials, properly proportioned, are then ground with water, thoroughly mixed in the form of slurry. In the dry process, raw materials are ground and mixed in a dry state. In both processes, the slurry or the dry material is fed to a rotary kiln inclined slightly form the horizontal where it is heated to more than 1,400 C.
A rotary kiln is frequently as much as 12 feet in diameter and 400 feet long.
The "raw meal" is fed into the higher end of the kiln and progresses to the lower end, moved by the rotation. On its way down, the "raw meal" is facing a burner blowing its flame under an upward forced draft.
At the lower end, the new substance, called clinker, is formed in pieces about the size of marbles. The heat is recuperated from the cooling of the red-hot clinker and returned to the kiln. The clinker remains to be ground into fine powder to which some gypsum is added to form cement.
Cement is then put in bags or carried in bulk to ready mix plants. Concrete is produced by mixing cement with fine (sand) or coarse aggregates (gravel or crushed stone) and water. Often, some chemicals are added to control setting time and plasticity.
The first important reaction to occur is the calcining of limestone (calcium carbonate CaCO3) into lime (calcium oxide CaO) and carbon dioxide (C02) at a temperature of 1 650 F (900 C).
The second reaction is the bonding of calcium oxide and silicates to form calcium silicates. Small amounts of calcium aluminate and calcium aluminoferrite are also formed. The relative proportions of these compounds determine the key properties of the resultant Portland cement and the type classification.
i o Cement Kiln Dust (CKD) Cement Kiln Dust (CKD), a fine granular material generated during cement production, is carried up by the combustion gases. The CKD is normally removed and collected by an air pollution control system. The collected CKD which is mainly made up of lime (CaO), K20, SO3, silica (SiO2) and alumina (A12O3) may be returned into the process or stocked.
The US Environmental Protection Agency published a report on the forseeable costs of conforming to future regulations on CDK dust (EPA, 1998). Among the interesting information published in this report, is the ratio of CDK production relative to clinker production depending on Kiln type (Table 1). As it can be appreciated, wet processes generate a greater production of CKD (between 11 and 17 %).
Table 1 Average CKD production vs clinker production depending on Kiln type Kiln Type Mean CKD / clinker production Non-hazardous fuel kiln Dry process 0,060 D preheating 0,024 Wet process 0,107 Hazardous fuel kiln Dry process 10,061 Kiln Type Mean CKD I clinker production Dry preheating 0,038 Wet process 0,166 The net CKD refuse (excluding CKD regenerated during the process) output by US cement plants is approximately 3,3 million tonnes per year.
In the above-mentioned EPA study, the baselines and the costs relating to conforming to future regulations were calculated for every affected plant. The total before-tax baseline costs, the inital conformity costs and the annual conformity costs respectively amount to 54,9; 98,5 and 43,7 millions US$. Out of 110 US plants, (62 %) would incur average annual costs of 646 000 US$, translating to 19,96 US$
per CKD tonne and 1,12 US$ per cement tonne produced. The total annual income for these 68 cement plants is estimated at 2,945 billion US$. The cost of conforming 1o to regulations would therefore represent 1,5 % of their income.
CQ2 emissions from cement Portland production CO2 emissions produced by cement production come from two sources:
1. Fossil fuel combustion required to heat the raw meal - 6 millions BTUs/tonne of cement produce 3/ tonne of CO2.
2. Calcining of limestone into lime -% tonne of C02/tonne of cement.
In Canada, one tonne of cement generates 0.5 tonne of CO2 from limestone conversion and about 0.35 tonne of CO2 from the combustion of fossil products, for a total of 0.85 tonne of CO2 for each tonne of cement produced.
The very high temperatures required for cement production allow for burning all sorts of materials such as solvents, paint, and tires. At these temperatures, the combustion is complete and pollution is reduced to a minimum.
The methods already known in the art for reducing CO2 emissions are the improvement of the energy efficiency of the process, the replacement of high carbon fuels by low carbon fuels, the use of waste as alternative fuel, the use of industrial waste containing lime and the use of fly ash to replace cement (15 to 35 %) in 5 concrete. Fly ash is a by-product of the combustion of pulverized coal in thermal power plants.
Literature abounds with a good number of processes destined to reducing carbon dioxide emissions by the cement industry. US6,240,859; GB587101; US5,744,078 propose above all an improvement of combustion efficiencies and recycling of fly lo ashes as cement additive. Patent DE4032557 suggests a method of handling aggregates and cement claiming improved energetic efficiency and in this way, preventing CO2 discharge by cement fabrics. Patent JP09-110485 uses absorption and volatilization of CO2 to produce energy. Finally, European patent advises reutilization of industrial exhaust gas, thus achieving improved combustion efficiency.
Japanese patent 10-130045 discloses cement waste recycling in the fabrication of regenerated cement, by the way claiming a reduction of CO2 emissions in the environment. As a matter of fact, combined recycling of CO2 and manufacture residues is often invoked as a means for reducing cementous polluting waste (JP2000-239670; JP2000-119049; JP09-168775). In some configurations (US6,187,277; JP07-068164; JP2000-300983), recycled solid materials can be directly used for carbon dioxide fixation of industrial gas exhausts. Another Japanese patent (JPIO-314758) was conceived so that COZ from the gaseous effluent of ceramic industries can be eliminated by introduction of residual water in cement plants.
CA1143910 describes a method allowing the use of CO2 from a waste flue gas and some waste material for manufacturing an asbestos free fibre reinforced cement. A
European untitled document (GB103290) also expects recycling of CO2 for,Portland cement manufacturing, in the same way as patent GB384060, which particularly uses a simple valve to isolate produced CO2 from other flue gases during the process.
Another way of reducing industrial CO2 emissions consists of transforming this gas to synthesis products of commercial value. Patent JP2000-072981 suggests carbon black production by utilizing exhaust gas in cement production through CO2 catalytic fixation whilst another (JP58-208117) allows for the manufacture of liquefied carbon dioxide from the waste gas of cement calcining kiln. Patent JP06-263665 deals with catalytic hydrogenation of carbon dioxide gas exhausted from cement factories for the production of chemicals such as methane and methanol.
A totally different approach preaches cement admixtures and compositions giving 1o low loads on the environment and discharging smaller amounts of carbon dioxide, as it is the case for patents FR2669918 and JP2001-039751.
Currently, many scripts emanate from scientists with the purpose of reducing emissions in general. Sinking CO2 in the seawater over the deep ocean floor (US 5,364,611; US 5,304,356; US 5,293,751) persists amongst the main considerations despite the many uncertainties and inconveniences associated with this method. Chemical fixation (CA 2352969) and selective adsorption of CO2 (US 5,667,561; JP02-000699) also stand amongst favoured methods in the literature. Membrane separation (JP11-235999) and chemical conversion in ether or methanol (US 6,248,795) offer interesting possibilities as well. One cannot help, but conclude exhaust gas absorption (US6,117,404; CA2255287; US5,888,256) remains one of the most promising methods and the very solubilization of concerned gases constitute the corner stone of all innovations in that field.
With this perspective, carbonic anhydrase has already been used for waste water treatment (US 6,110,370) and recently, for reducing CO2 emissions in enzymatic photobiorectors (US 5,614,378). Carbonic anhydrase is a highly reactive enzyme observed in most animal and vegetal species and thus, readily available.
Trachtenberg (US 6,143,556; CA 2222030) describes a system for gas processing with carbonic anhydrase without suggesting any specific application for cement fabrics. Michigan University introduced a photobioreactor for the conversion of CO2 with carbonic anhydrase, however destined to medical use as an artificial lung for life support (WO 9200380; US 5,614,378).
US patent 6,258,335 unveiled a catalytic process for carbon dioxide removal of ice exhaust by chemical fixation. This technology includes the optional use of carbonic anhydrase without particular consideration for cement plants. US Patent (4,743,545) exposed a bioreactor with hollow beads including catalyst, the latter being carbonic anhydrase if needed.
US 4,602,987 and US 4,761,209 disclose a method for extraction and utilization of oxygen from fluids. This system conceived for oxygen recovering especially includes lo a step for carbon dioxide removal by carbonic anhydrase ().
EP0991462; AU7753398; W09855210; CA2291785 in the name of the Applicant propose a countercurrent packed column bioreactor for treating carbon dioxide.
In this process, carbonic anhydrase is used immobilized or in a free state.
Although a great deal of efforts have been made to reduce in general, the greenhouse effect caused by the emissions of C02, there is still a need for further improvements and that mainly in the field of cement clinker production.
SUMMARY OF THE INVENTION
An object of the present invention is to satisfy the above-mentioned need.
According to the present invention, there is provided a process for producing cement clinker, comprising the steps of: a) providing a mixture of ground calcareous materials and ground argillaceous materials; b) heating the mixture of step a) to a temperature sufficient to calcine and fuse the ground materials to form the cement clinker, and thereby producing an exhaust gas containing C02; c) catalysing the hydration of at least a portion of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate ions and hydrogen ions; and d) adding to the solution obtained in step c) metal ions, and adjusting the pH of the solution to precipitate a carbonate of said metal.
As can be appreciated, the process according to the invention allows the carbon dioxide emissions from the production of cement clinker to be greatly reduced and even eliminated by simply catalysing the hydration of CO2 into a solution of bicarbonate ions and hydrogen ions. The bicarbonate ions are then reacted with metals ions to precipitate a carbonated metal harmless to the environment.
The hydration is preferably performed in the presence of an enzyme capable of catalysing the hydration of dissolved COZ into hydrogen ions and bicarbonate ions.
The enzyme is preferably carbonic anhydrase or an analogue thereof.
lo Also preferably, the metal ions are Ca++ and the carbonate is CaCO3. In such a case, the process preferably comprises after step d), the step of: e) recycling the CaCO3 obtained in step d) into the process by adding the CaCO3 to the mixture of step a). Also in this case, the ions Ca++ are preferably obtained from the dissolution of a material selected from the group consisting of CaCla, cement kiln dust and sea salts.
According to another preferred aspect, step c) of catalisation comprises the steps of:
feeding liquid H20 and at least a portion of the exhaust gas into a bioreactor containing therein a reaction chamber filled with said carbonic anhydrase immobilized on a support.
2o As can be appreciated, the process according to this preferred embodiment allows reduction of CO2 emissions at the source through a recycling loop integrated into the cement plant. The loop mainly consists of gas/liquid CO2 packed column absorption catalyzed by an immobilized enzyme (carbonic anhydrase) for the subsequent production of calcium carbonate (CaCO3). The loop is completed when the calcium carbonate is used as first class raw material for the fabrication of Portland cement.
According to this preferred aspect, the process has the advantages of recycling the CO2 into the process and providing a first class raw material for the production of the cement clinker.
The calcareous materials are preferably selected from the group consisting of limestone, marine shells and marl, and the argillaceous materials are preferably selected from the group consisting of clay, slate, sand, shale, and blast-furnace slags.
Also preferably, the mixture of step a) further comprises one or more material selected form the group consisting of aluminium, iron and chemical admixture.
According to the present invention, there is also provided a plant for producing cement clinker, comprising: a kiln for burning raw materials suitable for producing so cement clinker, the kiln having an inlet for receiving the raw materials, an outlet for discharging the cement clinker and a gas outlet for discharging an exhaust gas containing CO2. The plant also comprises means for catalysing the hydration of the CO2 contained in the exhaust gas into bicarbonate ions and hydrogen ions; and means for reacting the bicarbonate ions with metal ions to precipitate the carbonate of said metal.
The metal ions are preferably Ca++ and the carbonate is preferably CaCO3. In such a case, the plant preferably further comprises means for transferring the precipitate CaCO3 into the inlet of the kiln.
According to a preferred aspect of the invention, the means for catalysing the 2 o hydration of the CO2 comprises a bioreactor comprising a gas inlet for receiving at least a portion of the exhaust gas from the kiln; a liquid inlet for receiving an aqueous liquid, a reaction chamber in fluid communication with the gas inlet and the liquid inlet, the reaction chamber containing therein immobilized enzymes capable of catalysing the hydration of dissolved CO2 into bicarbonate ions and hydrogen ions;
and a liquid outlet in fluid communication with the reaction chamber for discharging a solution of bicarbonate ions and hydrogen ions.
The means for reacting the bicarbonate ions with metal ions is preferably a reaction reservoir.
Also preferably, the plant comprises cleansing means for cleansing the exhaust gas;
means for transferring the exhaust gas from the kiln to the cleansing means;
and means for transferring the clean exhaust gas from the cleansing means to the 5 catalysing means.
The objects, advantages and other features of the present invention will become more apparent upon reading of the following non restrictive description of the preferred embodiment thereof, given for the purpose of exemplification only with reference to the accompanying drawings.
1o DESCRIPTION OF THE DRAWING
Figure 1 is a schematic flow chart of a process according to the invention.
DESCRIPTION OF A PREFERRED EMBODIMENT
The process according to a preferred embodiment of the invention comprises a step where the CO2 emissions from the rotary kiln used in the cement production are transformed into bicarbonate ions by contacting the CO2 gas emissions with an aqueous liquid in a bioreactor containing enzymes capable of catalysing the hydration of CO2 into hydrogen and bicarbonate ions, and then reacting the bicarbonate ions with calcium ions so as to precipitate calcium carbonate (CaCO3) and recycling the same as a first class raw material in the rotary kiln used for producing the Portland cement clinker. The enzyme used is preferably carbonic anhydrase, and it is used free or immobilized on an appropriate support. .
Gaseous C02, considered the greatest contributor to the greenhouse effect, comes from the respiration of living organisms, fuel combustion and certain chemical reactions such as fossil fuel reforming. The CO2 produced by the two latter sources may be enzymatically treated with the enzymatic system described in W09855210 in the name of the applicant. This enzymatic system is a process for the transformation of gaseous CO2 into bicarbonate and hydrogen ions. The transformation reaction, usually a slow naturally occurring process, is catalyzed by an immobilized or free state enzyme in a specially made reactor. The enzymatic process catalyzes the hydration of dissolved carbon dioxide. The subsequent ionization equilibrium reaction produces bicarbonate and hydrogen ions. The following equations describe the relevant process :
Equation 1 Hydration : dissolved CO2 --> HZC03 Equation 2 Ionization : H2CO3 --> H+ + HC03 --> CO32" + H+
lo The carbonate ions, among others, are precipitated with calcium ions or others into carbonated mineral form.
Detailed description of a plant according to a preferred embodiment of the invention Referring to figure 1, the plant (10) for the production of cement clinker comprises a kiln schematically represented as box (12) for burning raw materials suitable for producing cement clinker. As commonly used in the production of cement clinker, the raw materials comprise calcareous (lime-bearing) and argillaceous (claylike) materials. The calcareous material may be quarried limestone, dredged marine shells or marl. The argillaceous materials could be clay, slate, shale, or special blast-furnace slags. As in a typical mill, the raw materials are preferably pulverized and 2 o handled either as wet suspension or as dry solids. The plant of the invention may use a dry process or a wet process, In the dry process, the pulverized materials are dried in a kiln drier and mixed in the proper proportion. In a wet process, the materials are processed as a wet slurry.
The kiln (12) has an inlet (14) for receiving the raw materials, an outlet (16) for discharging the cement clinker and a gas outlet (18) connected to a chimney stack (19) for discharging an exhaust gas containing CO2.
,. .,.,.,w.,.., .._._n._ .
The plant (10) further comprises a bioreactor (20) for catalysing the hydration of the C02 contained in the exhaust gas into 'bicarbonate ions and hydrogen ions. The biorector (20) is preferably as described in W0985521 0 in the name of the applicant.
It has a gas inlet (22) for receiving at least a portion of the exhaust gas, preferably ail the exhaust gas from the iciln (12) and a liquid inlet (24) for receiving an aqueous liquid. Although any liquid containing water could be used, it is easier to simply use water.. The bioreator (20) further includes a reaction chamber (26) in fluid communication with the gas inlet (22) and the liquid inlet (24), the reaction chamber (26) containing therein enzymes capable of catalysing the hydration of dissolved C02 io (meaning aqueous C02) into bicarbonate ions and hydrogen ions. The enzyrnes may -be in a free state or it may be immozbiiized on appro.priate supports. A
liquid outlet (28) in fluid communication with the reaction chamber (26) is provided' for discharging a solution of bicarbonate ions and hydrogen ions.
The plant (10) further comprises means, preferably a reaction reservoir (30), for reacting the bicarbonate ions obtained in the bioreactor (20) with metal ions to precipitate a carbonate of said metal.
According.to a preferred aspect , the bicarbonate ions are reacted with Ca++
ions obtained by the dissoiution in the reservoir (30) of a material selected from the group consisting of CaCl2, cement kiln dust and sea salts. In such a case, the precipitate obtained, CaCO3, is advantageously recycled in the process as a raw material fed to .
the kiln (12). As will be apparent for any person in the field, the plant (10) in such as case comprises means for transferring the precipitate CaCO3 into the inlet (14) of the kiln (12). As for example, in a wet process, the precipitate. could be transferred directly into the kiln by means of conventional piping and pump systems, or by means of any other transfer system known in the art. In a dry process, the precipitate will preferably be dried before being transferred to the kiln (12).
3 o The plant also preferably comprises cleansing means, such as a filter , for cleansing the exhaust gas coming from the ciment chimney (19) of kiln (12).
The filter (32) helps removing the CKD from the exhaust gas, which CDK may advantageously be used in the process for precipitating the CaCO3. As apparent to any person in the art, in such a case, the plant (10) comprises means for transferring the exhaust gas from the kiln to the cleansing means, and means for transferring the clean exhaust gas from the cleansing meansto the bioreactor (20). These transfer means may be, for example, any appropriate conduct systems.
Detailed Description of the process As defined above, and referring to figure 1, the process for producing cement clinker, comprising the steps of:
a) providing a mixture of ground calcareous materials and ground argillaceous materials as defined above;
b) heating the mixture of step a) to a temperature sufficient to calcine and fuse the ground materials to form the cement clinker, and thereby producing an exhaust gas containing C02;
c) catalysing the hydration of at least a portion of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate ions and hydrogen ions; and d) adding to the solution obtained in step c) metal ions, and adjusting the pH
of the solution to precipitate a carbonate of said metal.
The solution containing biocarbonate ions is preferably reacted with a solution containing Ca++ ions so to form CaCO3 which can be recycled into the process as a first class raw material.
The temperature sufficient to calcine and fuse the materials to form cement clinker is 1400 C or more, meaning substantially 1400 C or more.
The current industrial process for cement production relies on the following chemical reactions :
CaCO3 + A H CaO + CO2 CaO + Si02 + A <-> Cement The process initiates CO2 emissions from three different sources: two from combustion and the other from the breakdown of CaCO3 into CaO and CO2. The proposed complementary process intends, first, to transform CO2 according to the following bioreaction:
CO2 + H20 enzyme --* H+ + HC03 1 o Secondly, to set a reaction between the ion HCO3- and an ion such as calcium (Ca2+) which can be found for example in calcium chloride (CaCI2), CKD, sea salts or others CaCO3'will precipitate easily in an aqueous solution containing HC03 and Ca++ ions.
Thirdly, this CaCO3 can be used as first class raw material in the cement production process.
Estimates of the quantities involved are calculated using the molecular weights converted into tonnes.
CO2 (aq) + H20 enzyme -a H+ + HCOs (bicarbonate) tonnes : 44t 18t 1 t61 t HCO3 --+ C032" + H+ (Carbonate) tonnes : 61t 60t 1 t CaCI2 --> Ca2+ + 2 CI-tonnes : 66t 40t 26t Ca2+ + C03?" -> CaCO3 tonnes : 40t 60t 100 t The flow chart of figure 1 is more explicit in showing the main steps occurring in the cement production. The three CO2 emissions are identified. Two important sources are related to the energy required to heat, while the other is due to the lime 5 production (CaO). All these emissions proceed to the chimney stack (19).
Assuming the bioreactor (20) to be 100 % efficient, 44 tonnes of CO2 would produce 60 tonnes of carbonate ions. This amount of carbonate added to 66 tonnes of CaC12 could generate 100 tonnes of CaCO3.
The enzymes used in the bioreactor could be any enzyme capable of catalysing the 1 o hydration of CO2 into hydrogen ions and bicarbonate ions, for example, carbonic anhydrase or analogue thereof.
The calcium ions can be provided by using any chemical compound containing calcium and being capable of providing calcium ions in solution, for example, CaC12, sea salt, cement kiln dust or others.
15 Tables 2 and 3 show preliminary results of leaching essays performed on Cement Kiln Dust plant refuse and subsequent precipitation of bicarbonate ions by addition of filtered leachate. Analyses of major ion concentrations during the first leaching essay with 50 g of CKD in 500 mi water are shown in table 2. The most concentrated ions are potassium, calcium, sodium and chlorides, whereas aluminium, magnesium 2 o and baryum are weakly concentrated. A leaching pH of 12.33 allowed for recovery of a small portion of calcium present in the refuse. In spite of the calcite formation potential of this solution being 1.9 g calcite per liter, this cation dissolution potential may be increased by the variation of experimental parameters such as the pH, the temperature, the solid-liquid contact time and the solid concentration per unit of volume of water.
Table 2 Major ion concentrations in CDK refuse leachate Ions Mole I L
K 2.15E-01 Ca 1.90E-02 Na 2.30E-02 CI- 6.29E-02 Al 1.48E-05 Mg 1.67E-06 Ba 8.03E-06 PH 12.33 Further essays permitted to validate the precipitation potential of carbonate ions by the addition of refuse leachate to a sodium bicarbonate solution. In these essays, the pH of the leachate was not ajusted, rather, amounts of solids from the refuse were simply added in a volume of distilled water. The refuse added to water was mixed with agitation for two hours on a mechanical table agitator at room temperature of 22 C. Conductivity and pH measurements of the leachate were taken from samples before the precipitation step.
The following table shows the results of leaching essays by addition of 50, 100 and 1o 500 g of CKD to 500 ml of pure water. Firstly, the final leaching pH of sample PR1 (50 g CKD /500 ml) was 12.56 and that of the previous essay with the same refuse:water ratio was 12.33. This could explain precipitation of the mass at 0.7 g/L
which is slightly inferior to the 0.95 g/L precipitation potential of calcite (1.9 g/L/2;
dilution factor) calculated according to the 0.019 mol Ca/L in the leachate.
The solid mass increase in the volume of water (samples PR2 and PR3) allowed for an increase of the resulting precipitate mass although not in a proportional fashion. The very alcaline pH during leaching might explain this phenomenon. Even if the conductivity of sample PR3 is higher than for PR1 and PR2, the 0.25 g/L
precipitate mass is much weaker than the others. Chemical analyses will allow characterization of solid samples. Finally, all samples showed an effervescence reaction upon addition of diluted hydrochloric acid, which indicates precipitation of carbonate ions.
Electron microscopy analyses of the sample, as well as mineral identification through X-ray diffraction confirmed pure calcite precipitation into cubic crystals with an average edge or 5 m.
Table 3 Results of preliminary refuse leaching and bicarbonate ion precipitation essays Sample No CKD mass Conductivity pH of the NaHCO3 Mass of in 500 mi of leachate leachate concentrati precipita water mS/cm on added teobtain mol/L ed /L
PR1A 50 37.2 12.56 0.25 0.712 PR1 B 50 37.2 12.56 0.25 0.721 PR1C 50 37.2 12.56 0.25 0.724 PR2A 100 51.8 12.79 0.25 0.851 PR2B 100 51.8 12.79 0.25 0.826 PR2C 100 51.8 12.79 0.25 0.830 PR3A 500 94.6 13.13 0.25 0.247 Consequently, recovery of CO2 from the fabrication of cement and its transformation into bicarbonate ions in an enzymatic reactor, followed by the bicarbonate ion precipitation into calcite, through addition of leached refuse from cement plants as a source of calcium, and integration of the calcite as raw matter into the cement fabrication process allows for the recovery of CO2 responsible for the greenhouse effect and climatic changes. The perpetuel cycle of the present invention therefore 1o allows the elimination of CO2 emissions from cement plants into the atmosphere and the production of a reusable by-product in the cement fabrication process.
The precipitation of bicarbonate ions, resulting from the transformation of CO2, may also be achieved by the addition of external chemical salts, such as calcium chloride, magnesium chloride, baryum chloride, sea salt etc. Carbonated precipitates of these metals (CaCO3 - calcite, MgCO3 - magnesite, BaCO3 - witherite, CaMg(CO3)Z --dolomite and others) were obtained in laboratory essays their optimal precipitation pH determined.
For example, calcite and witherite were obtained at a pH as low as 8 and the increase of pH did not affect the composition of the precipitate. The concentration in magnesite however is optimal at a pH between 10 and 11 only. Precipitation by addition of sea salt is optimal at pH 10 but tends to form hydroxocomplexes with available cations at very alcaline pH. The essays were carried out with solutions of 0.1 mol/L in cations and bicarbonates, which in theory correspond to 10 g/L
calcite, 8.4 g/L magnesite and 19.7 g/L witherite.
Experimentation permitted to obtain up to 9.7 g/L calcite, 6.9 g/L magnesite and 19.4 g/L witherite. With sea salt, the maximal precipitate mass obtained was 5.3 g/L halite (NaCI) by evaporation during sample drying, hydromagnesite (Mg5(C03)4(OH)2.4H20), dolomite (CaMgCO3)2 and aragonite (CaCO3).
Also preferably, the process may comprise, prior to feeding the bioreactor with the CO2 emissions, a treatment unit for purifying the CO2 emissions and removing Zo waste particles from the same, such as dust, etc.
Although a preferred embodiment of the present invention has been described in detail herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to this precise embodiment and that various changes and modifications may be effected therein without departing from the scope or spirit of the present invention.
In the 25 production process, carbon dioxide emissions come from fossil fuel combustion and a calcination stage of limestone (CaCO3).
Portland cement is the binding agent that enables the formation of concrete, which will also include aggregates, air and water.
Portland cement is the result of a chemical combination of calcium (usually from limestone), silica (clay, sand and shale), alumina (bauxite), iron (ore) and small amounts of various chemicals called admixtures to which gypsum is added at the last grinding in order to control the cement setting process.
The production of one tonne of cement (2000) requires close to 3 500 tonnes of raw materials. Lime and silica account for approximately 85 % of the weight.
Two main categories of production processes are in use in this industry : the dry 1 o process kiln (70 % in the U.S.) and the wet process kiln (older). For both processes, the first step is similar. The raw materials are crushed for reduction to about 3 inches or smaller. In the wet process, the raw materials, properly proportioned, are then ground with water, thoroughly mixed in the form of slurry. In the dry process, raw materials are ground and mixed in a dry state. In both processes, the slurry or the dry material is fed to a rotary kiln inclined slightly form the horizontal where it is heated to more than 1,400 C.
A rotary kiln is frequently as much as 12 feet in diameter and 400 feet long.
The "raw meal" is fed into the higher end of the kiln and progresses to the lower end, moved by the rotation. On its way down, the "raw meal" is facing a burner blowing its flame under an upward forced draft.
At the lower end, the new substance, called clinker, is formed in pieces about the size of marbles. The heat is recuperated from the cooling of the red-hot clinker and returned to the kiln. The clinker remains to be ground into fine powder to which some gypsum is added to form cement.
Cement is then put in bags or carried in bulk to ready mix plants. Concrete is produced by mixing cement with fine (sand) or coarse aggregates (gravel or crushed stone) and water. Often, some chemicals are added to control setting time and plasticity.
The first important reaction to occur is the calcining of limestone (calcium carbonate CaCO3) into lime (calcium oxide CaO) and carbon dioxide (C02) at a temperature of 1 650 F (900 C).
The second reaction is the bonding of calcium oxide and silicates to form calcium silicates. Small amounts of calcium aluminate and calcium aluminoferrite are also formed. The relative proportions of these compounds determine the key properties of the resultant Portland cement and the type classification.
i o Cement Kiln Dust (CKD) Cement Kiln Dust (CKD), a fine granular material generated during cement production, is carried up by the combustion gases. The CKD is normally removed and collected by an air pollution control system. The collected CKD which is mainly made up of lime (CaO), K20, SO3, silica (SiO2) and alumina (A12O3) may be returned into the process or stocked.
The US Environmental Protection Agency published a report on the forseeable costs of conforming to future regulations on CDK dust (EPA, 1998). Among the interesting information published in this report, is the ratio of CDK production relative to clinker production depending on Kiln type (Table 1). As it can be appreciated, wet processes generate a greater production of CKD (between 11 and 17 %).
Table 1 Average CKD production vs clinker production depending on Kiln type Kiln Type Mean CKD / clinker production Non-hazardous fuel kiln Dry process 0,060 D preheating 0,024 Wet process 0,107 Hazardous fuel kiln Dry process 10,061 Kiln Type Mean CKD I clinker production Dry preheating 0,038 Wet process 0,166 The net CKD refuse (excluding CKD regenerated during the process) output by US cement plants is approximately 3,3 million tonnes per year.
In the above-mentioned EPA study, the baselines and the costs relating to conforming to future regulations were calculated for every affected plant. The total before-tax baseline costs, the inital conformity costs and the annual conformity costs respectively amount to 54,9; 98,5 and 43,7 millions US$. Out of 110 US plants, (62 %) would incur average annual costs of 646 000 US$, translating to 19,96 US$
per CKD tonne and 1,12 US$ per cement tonne produced. The total annual income for these 68 cement plants is estimated at 2,945 billion US$. The cost of conforming 1o to regulations would therefore represent 1,5 % of their income.
CQ2 emissions from cement Portland production CO2 emissions produced by cement production come from two sources:
1. Fossil fuel combustion required to heat the raw meal - 6 millions BTUs/tonne of cement produce 3/ tonne of CO2.
2. Calcining of limestone into lime -% tonne of C02/tonne of cement.
In Canada, one tonne of cement generates 0.5 tonne of CO2 from limestone conversion and about 0.35 tonne of CO2 from the combustion of fossil products, for a total of 0.85 tonne of CO2 for each tonne of cement produced.
The very high temperatures required for cement production allow for burning all sorts of materials such as solvents, paint, and tires. At these temperatures, the combustion is complete and pollution is reduced to a minimum.
The methods already known in the art for reducing CO2 emissions are the improvement of the energy efficiency of the process, the replacement of high carbon fuels by low carbon fuels, the use of waste as alternative fuel, the use of industrial waste containing lime and the use of fly ash to replace cement (15 to 35 %) in 5 concrete. Fly ash is a by-product of the combustion of pulverized coal in thermal power plants.
Literature abounds with a good number of processes destined to reducing carbon dioxide emissions by the cement industry. US6,240,859; GB587101; US5,744,078 propose above all an improvement of combustion efficiencies and recycling of fly lo ashes as cement additive. Patent DE4032557 suggests a method of handling aggregates and cement claiming improved energetic efficiency and in this way, preventing CO2 discharge by cement fabrics. Patent JP09-110485 uses absorption and volatilization of CO2 to produce energy. Finally, European patent advises reutilization of industrial exhaust gas, thus achieving improved combustion efficiency.
Japanese patent 10-130045 discloses cement waste recycling in the fabrication of regenerated cement, by the way claiming a reduction of CO2 emissions in the environment. As a matter of fact, combined recycling of CO2 and manufacture residues is often invoked as a means for reducing cementous polluting waste (JP2000-239670; JP2000-119049; JP09-168775). In some configurations (US6,187,277; JP07-068164; JP2000-300983), recycled solid materials can be directly used for carbon dioxide fixation of industrial gas exhausts. Another Japanese patent (JPIO-314758) was conceived so that COZ from the gaseous effluent of ceramic industries can be eliminated by introduction of residual water in cement plants.
CA1143910 describes a method allowing the use of CO2 from a waste flue gas and some waste material for manufacturing an asbestos free fibre reinforced cement. A
European untitled document (GB103290) also expects recycling of CO2 for,Portland cement manufacturing, in the same way as patent GB384060, which particularly uses a simple valve to isolate produced CO2 from other flue gases during the process.
Another way of reducing industrial CO2 emissions consists of transforming this gas to synthesis products of commercial value. Patent JP2000-072981 suggests carbon black production by utilizing exhaust gas in cement production through CO2 catalytic fixation whilst another (JP58-208117) allows for the manufacture of liquefied carbon dioxide from the waste gas of cement calcining kiln. Patent JP06-263665 deals with catalytic hydrogenation of carbon dioxide gas exhausted from cement factories for the production of chemicals such as methane and methanol.
A totally different approach preaches cement admixtures and compositions giving 1o low loads on the environment and discharging smaller amounts of carbon dioxide, as it is the case for patents FR2669918 and JP2001-039751.
Currently, many scripts emanate from scientists with the purpose of reducing emissions in general. Sinking CO2 in the seawater over the deep ocean floor (US 5,364,611; US 5,304,356; US 5,293,751) persists amongst the main considerations despite the many uncertainties and inconveniences associated with this method. Chemical fixation (CA 2352969) and selective adsorption of CO2 (US 5,667,561; JP02-000699) also stand amongst favoured methods in the literature. Membrane separation (JP11-235999) and chemical conversion in ether or methanol (US 6,248,795) offer interesting possibilities as well. One cannot help, but conclude exhaust gas absorption (US6,117,404; CA2255287; US5,888,256) remains one of the most promising methods and the very solubilization of concerned gases constitute the corner stone of all innovations in that field.
With this perspective, carbonic anhydrase has already been used for waste water treatment (US 6,110,370) and recently, for reducing CO2 emissions in enzymatic photobiorectors (US 5,614,378). Carbonic anhydrase is a highly reactive enzyme observed in most animal and vegetal species and thus, readily available.
Trachtenberg (US 6,143,556; CA 2222030) describes a system for gas processing with carbonic anhydrase without suggesting any specific application for cement fabrics. Michigan University introduced a photobioreactor for the conversion of CO2 with carbonic anhydrase, however destined to medical use as an artificial lung for life support (WO 9200380; US 5,614,378).
US patent 6,258,335 unveiled a catalytic process for carbon dioxide removal of ice exhaust by chemical fixation. This technology includes the optional use of carbonic anhydrase without particular consideration for cement plants. US Patent (4,743,545) exposed a bioreactor with hollow beads including catalyst, the latter being carbonic anhydrase if needed.
US 4,602,987 and US 4,761,209 disclose a method for extraction and utilization of oxygen from fluids. This system conceived for oxygen recovering especially includes lo a step for carbon dioxide removal by carbonic anhydrase ().
EP0991462; AU7753398; W09855210; CA2291785 in the name of the Applicant propose a countercurrent packed column bioreactor for treating carbon dioxide.
In this process, carbonic anhydrase is used immobilized or in a free state.
Although a great deal of efforts have been made to reduce in general, the greenhouse effect caused by the emissions of C02, there is still a need for further improvements and that mainly in the field of cement clinker production.
SUMMARY OF THE INVENTION
An object of the present invention is to satisfy the above-mentioned need.
According to the present invention, there is provided a process for producing cement clinker, comprising the steps of: a) providing a mixture of ground calcareous materials and ground argillaceous materials; b) heating the mixture of step a) to a temperature sufficient to calcine and fuse the ground materials to form the cement clinker, and thereby producing an exhaust gas containing C02; c) catalysing the hydration of at least a portion of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate ions and hydrogen ions; and d) adding to the solution obtained in step c) metal ions, and adjusting the pH of the solution to precipitate a carbonate of said metal.
As can be appreciated, the process according to the invention allows the carbon dioxide emissions from the production of cement clinker to be greatly reduced and even eliminated by simply catalysing the hydration of CO2 into a solution of bicarbonate ions and hydrogen ions. The bicarbonate ions are then reacted with metals ions to precipitate a carbonated metal harmless to the environment.
The hydration is preferably performed in the presence of an enzyme capable of catalysing the hydration of dissolved COZ into hydrogen ions and bicarbonate ions.
The enzyme is preferably carbonic anhydrase or an analogue thereof.
lo Also preferably, the metal ions are Ca++ and the carbonate is CaCO3. In such a case, the process preferably comprises after step d), the step of: e) recycling the CaCO3 obtained in step d) into the process by adding the CaCO3 to the mixture of step a). Also in this case, the ions Ca++ are preferably obtained from the dissolution of a material selected from the group consisting of CaCla, cement kiln dust and sea salts.
According to another preferred aspect, step c) of catalisation comprises the steps of:
feeding liquid H20 and at least a portion of the exhaust gas into a bioreactor containing therein a reaction chamber filled with said carbonic anhydrase immobilized on a support.
2o As can be appreciated, the process according to this preferred embodiment allows reduction of CO2 emissions at the source through a recycling loop integrated into the cement plant. The loop mainly consists of gas/liquid CO2 packed column absorption catalyzed by an immobilized enzyme (carbonic anhydrase) for the subsequent production of calcium carbonate (CaCO3). The loop is completed when the calcium carbonate is used as first class raw material for the fabrication of Portland cement.
According to this preferred aspect, the process has the advantages of recycling the CO2 into the process and providing a first class raw material for the production of the cement clinker.
The calcareous materials are preferably selected from the group consisting of limestone, marine shells and marl, and the argillaceous materials are preferably selected from the group consisting of clay, slate, sand, shale, and blast-furnace slags.
Also preferably, the mixture of step a) further comprises one or more material selected form the group consisting of aluminium, iron and chemical admixture.
According to the present invention, there is also provided a plant for producing cement clinker, comprising: a kiln for burning raw materials suitable for producing so cement clinker, the kiln having an inlet for receiving the raw materials, an outlet for discharging the cement clinker and a gas outlet for discharging an exhaust gas containing CO2. The plant also comprises means for catalysing the hydration of the CO2 contained in the exhaust gas into bicarbonate ions and hydrogen ions; and means for reacting the bicarbonate ions with metal ions to precipitate the carbonate of said metal.
The metal ions are preferably Ca++ and the carbonate is preferably CaCO3. In such a case, the plant preferably further comprises means for transferring the precipitate CaCO3 into the inlet of the kiln.
According to a preferred aspect of the invention, the means for catalysing the 2 o hydration of the CO2 comprises a bioreactor comprising a gas inlet for receiving at least a portion of the exhaust gas from the kiln; a liquid inlet for receiving an aqueous liquid, a reaction chamber in fluid communication with the gas inlet and the liquid inlet, the reaction chamber containing therein immobilized enzymes capable of catalysing the hydration of dissolved CO2 into bicarbonate ions and hydrogen ions;
and a liquid outlet in fluid communication with the reaction chamber for discharging a solution of bicarbonate ions and hydrogen ions.
The means for reacting the bicarbonate ions with metal ions is preferably a reaction reservoir.
Also preferably, the plant comprises cleansing means for cleansing the exhaust gas;
means for transferring the exhaust gas from the kiln to the cleansing means;
and means for transferring the clean exhaust gas from the cleansing means to the 5 catalysing means.
The objects, advantages and other features of the present invention will become more apparent upon reading of the following non restrictive description of the preferred embodiment thereof, given for the purpose of exemplification only with reference to the accompanying drawings.
1o DESCRIPTION OF THE DRAWING
Figure 1 is a schematic flow chart of a process according to the invention.
DESCRIPTION OF A PREFERRED EMBODIMENT
The process according to a preferred embodiment of the invention comprises a step where the CO2 emissions from the rotary kiln used in the cement production are transformed into bicarbonate ions by contacting the CO2 gas emissions with an aqueous liquid in a bioreactor containing enzymes capable of catalysing the hydration of CO2 into hydrogen and bicarbonate ions, and then reacting the bicarbonate ions with calcium ions so as to precipitate calcium carbonate (CaCO3) and recycling the same as a first class raw material in the rotary kiln used for producing the Portland cement clinker. The enzyme used is preferably carbonic anhydrase, and it is used free or immobilized on an appropriate support. .
Gaseous C02, considered the greatest contributor to the greenhouse effect, comes from the respiration of living organisms, fuel combustion and certain chemical reactions such as fossil fuel reforming. The CO2 produced by the two latter sources may be enzymatically treated with the enzymatic system described in W09855210 in the name of the applicant. This enzymatic system is a process for the transformation of gaseous CO2 into bicarbonate and hydrogen ions. The transformation reaction, usually a slow naturally occurring process, is catalyzed by an immobilized or free state enzyme in a specially made reactor. The enzymatic process catalyzes the hydration of dissolved carbon dioxide. The subsequent ionization equilibrium reaction produces bicarbonate and hydrogen ions. The following equations describe the relevant process :
Equation 1 Hydration : dissolved CO2 --> HZC03 Equation 2 Ionization : H2CO3 --> H+ + HC03 --> CO32" + H+
lo The carbonate ions, among others, are precipitated with calcium ions or others into carbonated mineral form.
Detailed description of a plant according to a preferred embodiment of the invention Referring to figure 1, the plant (10) for the production of cement clinker comprises a kiln schematically represented as box (12) for burning raw materials suitable for producing cement clinker. As commonly used in the production of cement clinker, the raw materials comprise calcareous (lime-bearing) and argillaceous (claylike) materials. The calcareous material may be quarried limestone, dredged marine shells or marl. The argillaceous materials could be clay, slate, shale, or special blast-furnace slags. As in a typical mill, the raw materials are preferably pulverized and 2 o handled either as wet suspension or as dry solids. The plant of the invention may use a dry process or a wet process, In the dry process, the pulverized materials are dried in a kiln drier and mixed in the proper proportion. In a wet process, the materials are processed as a wet slurry.
The kiln (12) has an inlet (14) for receiving the raw materials, an outlet (16) for discharging the cement clinker and a gas outlet (18) connected to a chimney stack (19) for discharging an exhaust gas containing CO2.
,. .,.,.,w.,.., .._._n._ .
The plant (10) further comprises a bioreactor (20) for catalysing the hydration of the C02 contained in the exhaust gas into 'bicarbonate ions and hydrogen ions. The biorector (20) is preferably as described in W0985521 0 in the name of the applicant.
It has a gas inlet (22) for receiving at least a portion of the exhaust gas, preferably ail the exhaust gas from the iciln (12) and a liquid inlet (24) for receiving an aqueous liquid. Although any liquid containing water could be used, it is easier to simply use water.. The bioreator (20) further includes a reaction chamber (26) in fluid communication with the gas inlet (22) and the liquid inlet (24), the reaction chamber (26) containing therein enzymes capable of catalysing the hydration of dissolved C02 io (meaning aqueous C02) into bicarbonate ions and hydrogen ions. The enzyrnes may -be in a free state or it may be immozbiiized on appro.priate supports. A
liquid outlet (28) in fluid communication with the reaction chamber (26) is provided' for discharging a solution of bicarbonate ions and hydrogen ions.
The plant (10) further comprises means, preferably a reaction reservoir (30), for reacting the bicarbonate ions obtained in the bioreactor (20) with metal ions to precipitate a carbonate of said metal.
According.to a preferred aspect , the bicarbonate ions are reacted with Ca++
ions obtained by the dissoiution in the reservoir (30) of a material selected from the group consisting of CaCl2, cement kiln dust and sea salts. In such a case, the precipitate obtained, CaCO3, is advantageously recycled in the process as a raw material fed to .
the kiln (12). As will be apparent for any person in the field, the plant (10) in such as case comprises means for transferring the precipitate CaCO3 into the inlet (14) of the kiln (12). As for example, in a wet process, the precipitate. could be transferred directly into the kiln by means of conventional piping and pump systems, or by means of any other transfer system known in the art. In a dry process, the precipitate will preferably be dried before being transferred to the kiln (12).
3 o The plant also preferably comprises cleansing means, such as a filter , for cleansing the exhaust gas coming from the ciment chimney (19) of kiln (12).
The filter (32) helps removing the CKD from the exhaust gas, which CDK may advantageously be used in the process for precipitating the CaCO3. As apparent to any person in the art, in such a case, the plant (10) comprises means for transferring the exhaust gas from the kiln to the cleansing means, and means for transferring the clean exhaust gas from the cleansing meansto the bioreactor (20). These transfer means may be, for example, any appropriate conduct systems.
Detailed Description of the process As defined above, and referring to figure 1, the process for producing cement clinker, comprising the steps of:
a) providing a mixture of ground calcareous materials and ground argillaceous materials as defined above;
b) heating the mixture of step a) to a temperature sufficient to calcine and fuse the ground materials to form the cement clinker, and thereby producing an exhaust gas containing C02;
c) catalysing the hydration of at least a portion of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate ions and hydrogen ions; and d) adding to the solution obtained in step c) metal ions, and adjusting the pH
of the solution to precipitate a carbonate of said metal.
The solution containing biocarbonate ions is preferably reacted with a solution containing Ca++ ions so to form CaCO3 which can be recycled into the process as a first class raw material.
The temperature sufficient to calcine and fuse the materials to form cement clinker is 1400 C or more, meaning substantially 1400 C or more.
The current industrial process for cement production relies on the following chemical reactions :
CaCO3 + A H CaO + CO2 CaO + Si02 + A <-> Cement The process initiates CO2 emissions from three different sources: two from combustion and the other from the breakdown of CaCO3 into CaO and CO2. The proposed complementary process intends, first, to transform CO2 according to the following bioreaction:
CO2 + H20 enzyme --* H+ + HC03 1 o Secondly, to set a reaction between the ion HCO3- and an ion such as calcium (Ca2+) which can be found for example in calcium chloride (CaCI2), CKD, sea salts or others CaCO3'will precipitate easily in an aqueous solution containing HC03 and Ca++ ions.
Thirdly, this CaCO3 can be used as first class raw material in the cement production process.
Estimates of the quantities involved are calculated using the molecular weights converted into tonnes.
CO2 (aq) + H20 enzyme -a H+ + HCOs (bicarbonate) tonnes : 44t 18t 1 t61 t HCO3 --+ C032" + H+ (Carbonate) tonnes : 61t 60t 1 t CaCI2 --> Ca2+ + 2 CI-tonnes : 66t 40t 26t Ca2+ + C03?" -> CaCO3 tonnes : 40t 60t 100 t The flow chart of figure 1 is more explicit in showing the main steps occurring in the cement production. The three CO2 emissions are identified. Two important sources are related to the energy required to heat, while the other is due to the lime 5 production (CaO). All these emissions proceed to the chimney stack (19).
Assuming the bioreactor (20) to be 100 % efficient, 44 tonnes of CO2 would produce 60 tonnes of carbonate ions. This amount of carbonate added to 66 tonnes of CaC12 could generate 100 tonnes of CaCO3.
The enzymes used in the bioreactor could be any enzyme capable of catalysing the 1 o hydration of CO2 into hydrogen ions and bicarbonate ions, for example, carbonic anhydrase or analogue thereof.
The calcium ions can be provided by using any chemical compound containing calcium and being capable of providing calcium ions in solution, for example, CaC12, sea salt, cement kiln dust or others.
15 Tables 2 and 3 show preliminary results of leaching essays performed on Cement Kiln Dust plant refuse and subsequent precipitation of bicarbonate ions by addition of filtered leachate. Analyses of major ion concentrations during the first leaching essay with 50 g of CKD in 500 mi water are shown in table 2. The most concentrated ions are potassium, calcium, sodium and chlorides, whereas aluminium, magnesium 2 o and baryum are weakly concentrated. A leaching pH of 12.33 allowed for recovery of a small portion of calcium present in the refuse. In spite of the calcite formation potential of this solution being 1.9 g calcite per liter, this cation dissolution potential may be increased by the variation of experimental parameters such as the pH, the temperature, the solid-liquid contact time and the solid concentration per unit of volume of water.
Table 2 Major ion concentrations in CDK refuse leachate Ions Mole I L
K 2.15E-01 Ca 1.90E-02 Na 2.30E-02 CI- 6.29E-02 Al 1.48E-05 Mg 1.67E-06 Ba 8.03E-06 PH 12.33 Further essays permitted to validate the precipitation potential of carbonate ions by the addition of refuse leachate to a sodium bicarbonate solution. In these essays, the pH of the leachate was not ajusted, rather, amounts of solids from the refuse were simply added in a volume of distilled water. The refuse added to water was mixed with agitation for two hours on a mechanical table agitator at room temperature of 22 C. Conductivity and pH measurements of the leachate were taken from samples before the precipitation step.
The following table shows the results of leaching essays by addition of 50, 100 and 1o 500 g of CKD to 500 ml of pure water. Firstly, the final leaching pH of sample PR1 (50 g CKD /500 ml) was 12.56 and that of the previous essay with the same refuse:water ratio was 12.33. This could explain precipitation of the mass at 0.7 g/L
which is slightly inferior to the 0.95 g/L precipitation potential of calcite (1.9 g/L/2;
dilution factor) calculated according to the 0.019 mol Ca/L in the leachate.
The solid mass increase in the volume of water (samples PR2 and PR3) allowed for an increase of the resulting precipitate mass although not in a proportional fashion. The very alcaline pH during leaching might explain this phenomenon. Even if the conductivity of sample PR3 is higher than for PR1 and PR2, the 0.25 g/L
precipitate mass is much weaker than the others. Chemical analyses will allow characterization of solid samples. Finally, all samples showed an effervescence reaction upon addition of diluted hydrochloric acid, which indicates precipitation of carbonate ions.
Electron microscopy analyses of the sample, as well as mineral identification through X-ray diffraction confirmed pure calcite precipitation into cubic crystals with an average edge or 5 m.
Table 3 Results of preliminary refuse leaching and bicarbonate ion precipitation essays Sample No CKD mass Conductivity pH of the NaHCO3 Mass of in 500 mi of leachate leachate concentrati precipita water mS/cm on added teobtain mol/L ed /L
PR1A 50 37.2 12.56 0.25 0.712 PR1 B 50 37.2 12.56 0.25 0.721 PR1C 50 37.2 12.56 0.25 0.724 PR2A 100 51.8 12.79 0.25 0.851 PR2B 100 51.8 12.79 0.25 0.826 PR2C 100 51.8 12.79 0.25 0.830 PR3A 500 94.6 13.13 0.25 0.247 Consequently, recovery of CO2 from the fabrication of cement and its transformation into bicarbonate ions in an enzymatic reactor, followed by the bicarbonate ion precipitation into calcite, through addition of leached refuse from cement plants as a source of calcium, and integration of the calcite as raw matter into the cement fabrication process allows for the recovery of CO2 responsible for the greenhouse effect and climatic changes. The perpetuel cycle of the present invention therefore 1o allows the elimination of CO2 emissions from cement plants into the atmosphere and the production of a reusable by-product in the cement fabrication process.
The precipitation of bicarbonate ions, resulting from the transformation of CO2, may also be achieved by the addition of external chemical salts, such as calcium chloride, magnesium chloride, baryum chloride, sea salt etc. Carbonated precipitates of these metals (CaCO3 - calcite, MgCO3 - magnesite, BaCO3 - witherite, CaMg(CO3)Z --dolomite and others) were obtained in laboratory essays their optimal precipitation pH determined.
For example, calcite and witherite were obtained at a pH as low as 8 and the increase of pH did not affect the composition of the precipitate. The concentration in magnesite however is optimal at a pH between 10 and 11 only. Precipitation by addition of sea salt is optimal at pH 10 but tends to form hydroxocomplexes with available cations at very alcaline pH. The essays were carried out with solutions of 0.1 mol/L in cations and bicarbonates, which in theory correspond to 10 g/L
calcite, 8.4 g/L magnesite and 19.7 g/L witherite.
Experimentation permitted to obtain up to 9.7 g/L calcite, 6.9 g/L magnesite and 19.4 g/L witherite. With sea salt, the maximal precipitate mass obtained was 5.3 g/L halite (NaCI) by evaporation during sample drying, hydromagnesite (Mg5(C03)4(OH)2.4H20), dolomite (CaMgCO3)2 and aragonite (CaCO3).
Also preferably, the process may comprise, prior to feeding the bioreactor with the CO2 emissions, a treatment unit for purifying the CO2 emissions and removing Zo waste particles from the same, such as dust, etc.
Although a preferred embodiment of the present invention has been described in detail herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to this precise embodiment and that various changes and modifications may be effected therein without departing from the scope or spirit of the present invention.
Claims (18)
1. A process for producing cement clinker, comprising the steps of:
a) providing a mixture of ground calcareous materials and ground argillaceous materials;
b) heating the mixture of step a) to a temperature sufficient to calcine and fuse the ground materials to form the cement clinker, and thereby producing an exhaust gas containing CO2;
c) catalysing the hydration of at least a portion of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate ions and hydrogen ions; and d) adding to the solution obtained in step c) metal ions, and adjusting the pH of the solution to precipitate a carbonate of said metal.
a) providing a mixture of ground calcareous materials and ground argillaceous materials;
b) heating the mixture of step a) to a temperature sufficient to calcine and fuse the ground materials to form the cement clinker, and thereby producing an exhaust gas containing CO2;
c) catalysing the hydration of at least a portion of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate ions and hydrogen ions; and d) adding to the solution obtained in step c) metal ions, and adjusting the pH of the solution to precipitate a carbonate of said metal.
2. The process as claimed in claim 1, wherein said hydration is performed in the presence of an enzyme for catalysing the hydration of dissolved CO2 into hydrogen ions and bicarbonate ions.
3. The process as claimed in claim 1 wherein, the metal ions are Ca++ and the carbonate is CaCO3.
4. The process as claimed in claim 3, comprising, after step d), the step of:
e) recycling the CaCO3 obtained in step d) into the process by adding the CaCO3 to the mixture of step a).
e) recycling the CaCO3 obtained in step d) into the process by adding the CaCO3 to the mixture of step a).
5. The process as claimed in claim 2, wherein the enzyme used in step c) is carbonic anhydrase or an analogue thereof.
6. The process as claimed in claim 5, wherein step c) comprises the steps of:
- feeding liquid H2O and at least a portion of the exhaust gas into a bioreactor containing therein a reaction chamber filled with said carbonic anhydrase immobilized on a support.
- feeding liquid H2O and at least a portion of the exhaust gas into a bioreactor containing therein a reaction chamber filled with said carbonic anhydrase immobilized on a support.
7. The process as defined in claim 3, wherein the ions Ca++ are obtained from the dissolution of a material selected from the group consisting of CaCl2, cement kiln dust and sea salts.
8. The process as defined in claim 1, wherein the calcareous materials are selected from the group consisting of limestone, marine shells and marl.
9. The process as defined in claim 1 wherein the argillaceous materials are selected from the group consisting of clay, slate, sand, shale, and blast-furnace slags.
10. The process as claimed in claim 1, wherein the mixture of step a) further comprises one or more material selected form the group consisting of aluminium, iron and chemical admixture.
11. The process as claimed in claim 1, wherein the metal ions is selected from the group consisting of Ca++, Mg++, Ba++, CaMg++ and Na+.
12. The process as claimed in claim 1, comprising, prior to step c) of hydration, the step of:
- cleansing the exhaust gas for removing waste particles.
- cleansing the exhaust gas for removing waste particles.
13. The process as claimed in claim 1, wherein said temperature sufficient to calcine and fuse the ground materials is at least 1400°C.
14. A plant for producing cement clinker, comprising:
- a kiln for burning raw materials for producing cement clinker, the kiln having an inlet for receiving the raw materials, an outlet for discharging the cement clinker and a gas outlet for discharging an exhaust gas containing CO2;
- means for catalysing the hydration of the CO2 contained in the exhaust gas into bicarbonate ions and hydrogen ions; and - means for reacting the bicarbonate ions with metal ions to precipitate the carbonate of said metal.
- a kiln for burning raw materials for producing cement clinker, the kiln having an inlet for receiving the raw materials, an outlet for discharging the cement clinker and a gas outlet for discharging an exhaust gas containing CO2;
- means for catalysing the hydration of the CO2 contained in the exhaust gas into bicarbonate ions and hydrogen ions; and - means for reacting the bicarbonate ions with metal ions to precipitate the carbonate of said metal.
15. The plant as claimed in claim 14, wherein said metal ions are Ca++ and the carbonate is CaCO3 and wherein the plant further comprises:
- means for transferring the precipitate CaCO3 into the inlet of the kiln.
- means for transferring the precipitate CaCO3 into the inlet of the kiln.
16. The plant as claimed in claim 14, wherein the means for catalysing the hydration of the CO2 comprises a bioreactor comprising:
- a gas inlet for receiving at least a portion of the exhaust gas from the kiln;
- a liquid inlet for receiving an aqueous liquid;
- a reaction chamber in fluid communication with the gas inlet and the liquid inlet, the reaction chamber containing therein immobilized enzymes for catalysing the hydration of dissolved CO2 into bicarbonate ions and hydrogen ions; and - a liquid outlet in fluid communication with the reaction chamber for discharging a solution of bicarbonate ions and hydrogen ions.
- a gas inlet for receiving at least a portion of the exhaust gas from the kiln;
- a liquid inlet for receiving an aqueous liquid;
- a reaction chamber in fluid communication with the gas inlet and the liquid inlet, the reaction chamber containing therein immobilized enzymes for catalysing the hydration of dissolved CO2 into bicarbonate ions and hydrogen ions; and - a liquid outlet in fluid communication with the reaction chamber for discharging a solution of bicarbonate ions and hydrogen ions.
17. The plant as claimed in claim 14, wherein the means for reacting the bicarbonate ions with metal ions is a reaction tank.
18. A plant as claimed in claim 14, comprising:
- cleansing means for cleansing the exhaust gas; -means for transferring the exhaust gas from the kiln to the cleansing means; and - means for transferring the clean exhaust gas from the cleansing means to the catalysing means.
- cleansing means for cleansing the exhaust gas; -means for transferring the exhaust gas from the kiln to the cleansing means; and - means for transferring the clean exhaust gas from the cleansing means to the catalysing means.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US28332701P | 2001-04-13 | 2001-04-13 | |
| US60/283,327 | 2001-04-13 | ||
| PCT/CA2002/000517 WO2002083591A1 (en) | 2001-04-13 | 2002-04-12 | A process and a plant for the production of portland cement clinker |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2443222A1 CA2443222A1 (en) | 2002-10-24 |
| CA2443222C true CA2443222C (en) | 2009-09-15 |
Family
ID=23085492
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002443222A Expired - Fee Related CA2443222C (en) | 2001-04-13 | 2002-04-12 | A process and a plant for the production of portland cement clinker |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US6908507B2 (en) |
| EP (1) | EP1377531B1 (en) |
| AT (1) | ATE368015T1 (en) |
| CA (1) | CA2443222C (en) |
| DE (1) | DE60221373D1 (en) |
| WO (1) | WO2002083591A1 (en) |
Families Citing this family (88)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2394073A1 (en) * | 2002-07-16 | 2004-01-16 | Cascades Inc., Recherche Et Developpement | Process for synthesizing precipitated calcium carbonate using an enzyme |
| CA2405635A1 (en) * | 2002-09-27 | 2004-03-27 | C02 Solution Inc. | A process and a plant for the production of useful carbonated species and for the recycling of carbon dioxide emissions from power plants |
| US7607482B2 (en) | 2005-09-09 | 2009-10-27 | Halliburton Energy Services, Inc. | Settable compositions comprising cement kiln dust and swellable particles |
| CA2535521C (en) * | 2005-02-07 | 2013-07-09 | Co2 Solution Inc. | Process and installation for the fractionation of air into specific gases |
| EP1899043A4 (en) * | 2005-07-05 | 2011-03-23 | Greensols Australia Pty Ltd | Preparation and use of cationic halides, sequestration of carbon dioxide |
| US20070048856A1 (en) * | 2005-07-27 | 2007-03-01 | Carmen Parent | Gas purification apparatus and process using biofiltration and enzymatic reactions |
| US8327939B2 (en) | 2005-09-09 | 2012-12-11 | Halliburton Energy Services, Inc. | Settable compositions comprising cement kiln dust and rice husk ash and methods of use |
| US8297357B2 (en) | 2005-09-09 | 2012-10-30 | Halliburton Energy Services Inc. | Acid-soluble cement compositions comprising cement kiln dust and/or a natural pozzolan and methods of use |
| US8522873B2 (en) | 2005-09-09 | 2013-09-03 | Halliburton Energy Services, Inc. | Spacer fluids containing cement kiln dust and methods of use |
| US8333240B2 (en) * | 2005-09-09 | 2012-12-18 | Halliburton Energy Services, Inc. | Reduced carbon footprint settable compositions for use in subterranean formations |
| US7607484B2 (en) | 2005-09-09 | 2009-10-27 | Halliburton Energy Services, Inc. | Foamed cement compositions comprising oil-swellable particles and methods of use |
| US8555967B2 (en) | 2005-09-09 | 2013-10-15 | Halliburton Energy Services, Inc. | Methods and systems for evaluating a boundary between a consolidating spacer fluid and a cement composition |
| US8505630B2 (en) | 2005-09-09 | 2013-08-13 | Halliburton Energy Services, Inc. | Consolidating spacer fluids and methods of use |
| US8609595B2 (en) | 2005-09-09 | 2013-12-17 | Halliburton Energy Services, Inc. | Methods for determining reactive index for cement kiln dust, associated compositions, and methods of use |
| US8281859B2 (en) | 2005-09-09 | 2012-10-09 | Halliburton Energy Services Inc. | Methods and compositions comprising cement kiln dust having an altered particle size |
| US8307899B2 (en) | 2005-09-09 | 2012-11-13 | Halliburton Energy Services, Inc. | Methods of plugging and abandoning a well using compositions comprising cement kiln dust and pumicite |
| US8403045B2 (en) | 2005-09-09 | 2013-03-26 | Halliburton Energy Services, Inc. | Settable compositions comprising unexpanded perlite and methods of cementing in subterranean formations |
| US9809737B2 (en) | 2005-09-09 | 2017-11-07 | Halliburton Energy Services, Inc. | Compositions containing kiln dust and/or biowaste ash and methods of use |
| US8672028B2 (en) | 2010-12-21 | 2014-03-18 | Halliburton Energy Services, Inc. | Settable compositions comprising interground perlite and hydraulic cement |
| US9051505B2 (en) | 2005-09-09 | 2015-06-09 | Halliburton Energy Services, Inc. | Placing a fluid comprising kiln dust in a wellbore through a bottom hole assembly |
| US8950486B2 (en) | 2005-09-09 | 2015-02-10 | Halliburton Energy Services, Inc. | Acid-soluble cement compositions comprising cement kiln dust and methods of use |
| US9006155B2 (en) | 2005-09-09 | 2015-04-14 | Halliburton Energy Services, Inc. | Placing a fluid comprising kiln dust in a wellbore through a bottom hole assembly |
| US8505629B2 (en) | 2005-09-09 | 2013-08-13 | Halliburton Energy Services, Inc. | Foamed spacer fluids containing cement kiln dust and methods of use |
| US9150773B2 (en) | 2005-09-09 | 2015-10-06 | Halliburton Energy Services, Inc. | Compositions comprising kiln dust and wollastonite and methods of use in subterranean formations |
| US9676989B2 (en) | 2005-09-09 | 2017-06-13 | Halliburton Energy Services, Inc. | Sealant compositions comprising cement kiln dust and tire-rubber particles and method of use |
| US7789150B2 (en) | 2005-09-09 | 2010-09-07 | Halliburton Energy Services Inc. | Latex compositions comprising pozzolan and/or cement kiln dust and methods of use |
| US9023150B2 (en) | 2005-09-09 | 2015-05-05 | Halliburton Energy Services, Inc. | Acid-soluble cement compositions comprising cement kiln dust and/or a natural pozzolan and methods of use |
| US7743828B2 (en) | 2005-09-09 | 2010-06-29 | Halliburton Energy Services, Inc. | Methods of cementing in subterranean formations using cement kiln cement kiln dust in compositions having reduced Portland cement content |
| EP2438978B1 (en) * | 2006-03-10 | 2013-11-13 | C-Quest Technologies International LLC | Method for recycling industrial by-products |
| AU2012200916B2 (en) * | 2006-03-10 | 2013-06-27 | C-Quest Technologies International Llc | Carbon dioxide sequestration materials and processes |
| FR2908327B1 (en) * | 2006-11-09 | 2009-01-30 | Air Liquide | PROCESS FOR MANUFACTURING CLINKER WITH CONTROLLED CO2 EMISSION |
| SI1923367T1 (en) | 2006-11-13 | 2013-11-29 | Lafarge | Process for the production of cement |
| EP2158627A2 (en) * | 2007-05-04 | 2010-03-03 | Akermin, Inc. | Immobilized enzymes and uses thereof |
| EP2134664A4 (en) * | 2007-05-24 | 2010-04-14 | Calera Corp | Hydraulic cements comprising carbonate compounds compositions |
| CA2659451C (en) * | 2007-06-28 | 2011-04-12 | Calera Corporation | Desalination methods and systems that include carbonate compound precipitation |
| US7753618B2 (en) * | 2007-06-28 | 2010-07-13 | Calera Corporation | Rocks and aggregate, and methods of making and using the same |
| FR2921059B1 (en) * | 2007-09-14 | 2011-06-24 | Rech S Geol Et Minieres Brgm Bureau De | PROCESS AND INSTALLATION OF CLINKER PRODUCTION |
| US7993616B2 (en) | 2007-09-19 | 2011-08-09 | C-Quest Technologies LLC | Methods and devices for reducing hazardous air pollutants |
| US20100239467A1 (en) | 2008-06-17 | 2010-09-23 | Brent Constantz | Methods and systems for utilizing waste sources of metal oxides |
| KR20100105860A (en) | 2007-12-28 | 2010-09-30 | 칼레라 코포레이션 | Methods of sequestering co2 |
| US7754169B2 (en) * | 2007-12-28 | 2010-07-13 | Calera Corporation | Methods and systems for utilizing waste sources of metal oxides |
| US7749476B2 (en) * | 2007-12-28 | 2010-07-06 | Calera Corporation | Production of carbonate-containing compositions from material comprising metal silicates |
| US7919064B2 (en) * | 2008-02-12 | 2011-04-05 | Michigan Technological University | Capture and sequestration of carbon dioxide in flue gases |
| GB0806148D0 (en) * | 2008-04-04 | 2008-05-14 | Johnson Matthey Plc | Process for preparing catalysts |
| JP4730394B2 (en) * | 2008-05-07 | 2011-07-20 | 三菱マテリアル株式会社 | CO2 gas recovery method and recovery facility in cement manufacturing facility |
| JP4730455B2 (en) * | 2008-05-07 | 2011-07-20 | 三菱マテリアル株式会社 | CO2 gas recovery method and recovery facility in cement manufacturing facility |
| JP4730393B2 (en) * | 2008-05-07 | 2011-07-20 | 三菱マテリアル株式会社 | CO2 gas recovery method and recovery facility in cement manufacturing facility |
| EP2289858B1 (en) | 2008-05-07 | 2015-06-24 | Mitsubishi Materials Corporation | Method and apparatus for recovering co2 gas in cement production equipment |
| AU2009271304B2 (en) | 2008-07-16 | 2013-08-15 | Eleryc, Inc. | Low-energy 4-cell electrochemical system with carbon dioxide gas |
| CN101910469A (en) | 2008-07-16 | 2010-12-08 | 卡勒拉公司 | Co2 utilization in electrochemical systems |
| US7993500B2 (en) | 2008-07-16 | 2011-08-09 | Calera Corporation | Gas diffusion anode and CO2 cathode electrolyte system |
| US7966250B2 (en) | 2008-09-11 | 2011-06-21 | Calera Corporation | CO2 commodity trading system and method |
| KR20110087273A (en) | 2008-09-29 | 2011-08-02 | 아커민 인코퍼레이티드 | Process for accelerated capture of carbon dioxide |
| US7815880B2 (en) * | 2008-09-30 | 2010-10-19 | Calera Corporation | Reduced-carbon footprint concrete compositions |
| CA2700770C (en) | 2008-09-30 | 2013-09-03 | Calera Corporation | Co2-sequestering formed building materials |
| US7939336B2 (en) | 2008-09-30 | 2011-05-10 | Calera Corporation | Compositions and methods using substances containing carbon |
| US8869477B2 (en) | 2008-09-30 | 2014-10-28 | Calera Corporation | Formed building materials |
| CN101939269B (en) * | 2008-10-22 | 2014-08-06 | 卡勒拉公司 | Reduced-carbon footprint concrete compositions |
| AU2009287463B2 (en) * | 2008-10-31 | 2010-09-02 | Arelac, Inc. | Non-cementitious compositions comprising CO2 sequestering additives |
| US9133581B2 (en) | 2008-10-31 | 2015-09-15 | Calera Corporation | Non-cementitious compositions comprising vaterite and methods thereof |
| US7790012B2 (en) * | 2008-12-23 | 2010-09-07 | Calera Corporation | Low energy electrochemical hydroxide system and method |
| WO2010081007A2 (en) * | 2009-01-09 | 2010-07-15 | Codexis, Inc. | Carbonic anhydrase polypeptides and uses thereof |
| WO2010093716A1 (en) | 2009-02-10 | 2010-08-19 | Calera Corporation | Low-voltage alkaline production using hydrogen and electrocatlytic electrodes |
| BRPI1009150A2 (en) | 2009-03-02 | 2016-03-01 | Calera Corp | multi-pollutant gas flow control systems and methods |
| AU2010201373A1 (en) | 2009-03-10 | 2010-09-30 | Calera Corporation | System and methods for processing CO2 |
| US8474387B2 (en) * | 2009-06-08 | 2013-07-02 | Flsmidth A/S | Method and apparatus for incineration of combustible waste |
| US7993511B2 (en) | 2009-07-15 | 2011-08-09 | Calera Corporation | Electrochemical production of an alkaline solution using CO2 |
| AU2010281323B2 (en) | 2009-08-04 | 2015-09-03 | Saipem S.P.A. | Process for co2 capture using carbonates and biocatalysts |
| EP3278862A1 (en) | 2009-08-04 | 2018-02-07 | CO2 Solutions Inc. | Process for co2 capture using micro-particles comprising biocatalysts |
| WO2011049996A1 (en) * | 2009-10-19 | 2011-04-28 | Calera Corporation | Methods and systems for treating industrial waste gases |
| FR2951716B1 (en) * | 2009-10-22 | 2013-03-08 | Lafarge Sa | COMPOSITION FOR CAPTURING CO2 |
| EP2588597A4 (en) | 2010-06-30 | 2013-12-25 | Codexis Inc | Chemically modified carbonic anhydrases useful in carbon capture systems |
| US8354261B2 (en) | 2010-06-30 | 2013-01-15 | Codexis, Inc. | Highly stable β-class carbonic anhydrases useful in carbon capture systems |
| WO2012003299A2 (en) | 2010-06-30 | 2012-01-05 | Codexis, Inc. | Highly stable beta-class carbonic anhydrases useful in carbon capture systems |
| CA2807102C (en) | 2010-07-31 | 2018-08-21 | Myriant Corporation | Improved fermentation process for the production of organic acids |
| EP2476478A1 (en) * | 2011-01-12 | 2012-07-18 | Lafarge | Process for carbon dioxide removal from a gas by contacting it with a solid |
| DE102011001817A1 (en) | 2011-04-05 | 2012-10-11 | Thyssenkrupp Polysius Ag | Method and plant for producing cement and precipitated calcium carbonate |
| US20130045514A1 (en) * | 2011-08-17 | 2013-02-21 | Roberto Barbero | Biologically Catalyzed Mineralization of Carbon Dioxide |
| WO2014039578A1 (en) * | 2012-09-04 | 2014-03-13 | Blue Planet, Ltd. | Carbon sequestration methods and systems, and compositions produced thereby |
| EP2912172B1 (en) | 2012-10-29 | 2018-12-05 | CO2 Solutions Inc. | Techniques for co2 capture using sulfurihydrogenibium sp. carbonic anhydrase |
| WO2014144848A1 (en) | 2013-03-15 | 2014-09-18 | Blue Planet, Ltd. | Highly reflective microcrystalline/amorphous materials, and methods for making and using the same |
| CA2890582C (en) | 2014-08-27 | 2022-07-19 | Normand Voyer | Co2 capture methods using thermovibrio ammonificans carbonic anhydrase |
| CN109310951A (en) | 2016-03-25 | 2019-02-05 | 蓝色星球有限公司 | Carbon dioxide (the CO that ammonia mediates2) method of seal and system |
| US11712654B2 (en) * | 2017-03-02 | 2023-08-01 | Blue Planet Systems Corporation | Direct air capture (DAC) carbon dioxide (CO2) sequestration methods and systems |
| CN111892313A (en) * | 2020-08-27 | 2020-11-06 | 南京凯盛开能环保能源有限公司 | System and method for purifying and trapping carbon dioxide suitable for cement kiln |
| CN115403286A (en) * | 2021-05-28 | 2022-11-29 | 中国科学院大连化学物理研究所 | Method for preparing clinker and CO-producing CO by using solid reducing agent to catalyze limestone to reduce and decompose |
| WO2023208755A1 (en) | 2022-04-27 | 2023-11-02 | Evonik Operations Gmbh | Storage of carbon dioxide released from lime |
| CN115403314B (en) * | 2022-09-13 | 2023-07-11 | 广东省科学院江门产业技术研究院有限公司 | Negative carbon structure material and preparation method thereof |
Family Cites Families (46)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB103290A (en) | 1916-01-07 | 1917-12-06 | Ernst Waldemar Jungner | Improved Process of Producing Alkali Carbonate and Hydraulic Cement from Alkaliferous Silicate Minerals. |
| GB384060A (en) | 1931-11-16 | 1932-12-01 | Hubert Alexander Gill | Improvements in processes of and plants for burning cement, lime and like materials |
| GB587101A (en) | 1945-01-03 | 1947-04-14 | Arthur Gustav Guttmann | Improvements in and relating to the curing of concrete or precast stone by means of carbon dioxide |
| GB1426335A (en) * | 1972-09-04 | 1976-02-25 | Woodall Duckham Ltd | Treatment of inorganic dust |
| AU541464B2 (en) | 1978-08-04 | 1985-01-10 | Csr Limited | Manufacturing fibre reinforced building element |
| US4743545A (en) | 1984-08-09 | 1988-05-10 | Torobin Leonard B | Hollow porous microspheres containing biocatalyst |
| DE3218232A1 (en) | 1982-05-14 | 1984-02-09 | Quittkat, Wolfram G., Dr.-Ing., 8183 Rottach-Egern | Process for burning carbonate-type raw materials |
| JPS58208117A (en) | 1982-05-27 | 1983-12-03 | Showa Denko Kk | Manufacture of liquefied carbon dioxide |
| US4602987A (en) | 1984-09-24 | 1986-07-29 | Aquanautics Corporation | System for the extraction and utilization of oxygen from fluids |
| US4716027A (en) * | 1986-07-25 | 1987-12-29 | Passamaquoddy Tribe, A Sovereign Indian Tribe Recognized By The Government Of The United States Of America | Method for simultaneously scrubbing cement kiln exhaust gas and producing useful by-products therefrom |
| JPH02699A (en) | 1987-10-24 | 1990-01-05 | Seibu Gas Kk | Removal of carbon dioxide and moisture from gas in town gas production process |
| JP3021004B2 (en) | 1989-07-19 | 2000-03-15 | 三菱重工業株式会社 | Method and apparatus for introducing carbon dioxide into the deep sea |
| EP0429154B1 (en) | 1989-11-21 | 1994-12-21 | Mitsubishi Jukogyo Kabushiki Kaisha | Method for the fixation of carbon dioxide and apparatus for the treatment of carbon dioxide |
| US5614378A (en) | 1990-06-28 | 1997-03-25 | The Regents Of The University Of Michigan | Photobioreactors and closed ecological life support systems and artifificial lungs containing the same |
| WO1992000380A1 (en) | 1990-06-28 | 1992-01-09 | The Regents Of The University Of Michigan | Photobioreactors and closed ecological life support systems and artificial lungs containing the same |
| DE4032557C2 (en) | 1990-09-26 | 1996-10-02 | Ruhrkohle Ag | Containers for the transport and handling of building materials consisting essentially of aggregates and cement |
| FR2669918B3 (en) | 1990-12-04 | 1993-02-19 | Joseph Davidovits | PROCESS FOR OBTAINING A GEOPOLYMER CEMENT, WITHOUT EMISSION OF CARBONIC GAS CO2 AND PRODUCTS OBTAINED BY THIS PROCESS. |
| JP3146216B2 (en) | 1993-03-12 | 2001-03-12 | 工業技術院長 | CO2 catalytic hydrogenation |
| JPH0768164A (en) | 1993-09-03 | 1995-03-14 | Kyoei Kogyo Kk | Carbon dioxide fixing material and carbon dioxide fixing filter |
| CN1128502A (en) | 1994-03-15 | 1996-08-07 | 罗林帕克阿施塔化学技术进出口公司 | Pollution control method and device enabling complete removal of nitrogen oxides from combustion gases in combustion processes |
| US5667561A (en) | 1995-01-26 | 1997-09-16 | Agency Of Industrial Science & Technology, Ministry Of International Trade & Industry | Method for selective separation of carbon dioxide from waste gas of combustion |
| CA2222030C (en) | 1995-06-07 | 2007-05-29 | Michael C. Trachtenberg | Enzyme systems for gas processing |
| WO1996040414A1 (en) | 1995-06-07 | 1996-12-19 | Trachtenberg Michael C | Enzyme systems for gas processing |
| JPH09110485A (en) | 1995-10-09 | 1997-04-28 | Ishikawajima Harima Heavy Ind Co Ltd | Cement production equipment |
| JPH09168775A (en) | 1995-12-19 | 1997-06-30 | Yasuo Arai | Method for treating concrete waste material to reutilize the same as resources |
| JPH09262432A (en) | 1996-03-29 | 1997-10-07 | Kansai Electric Power Co Inc:The | Method for recovering basic amine compound in waste gas of decarboxylation column |
| US5744078A (en) | 1996-09-03 | 1998-04-28 | Dpd, Inc. | Accelerated processing of cement-bonded particleboard and fiberboard |
| US5888256A (en) | 1996-09-11 | 1999-03-30 | Morrison; Garrett L. | Managed composition of waste-derived fuel |
| JPH10130045A (en) | 1996-10-24 | 1998-05-19 | Mitsubishi Materials Corp | Regeneratable concrete material and method for recycling waste concrete material made from this concrete material |
| US5766339A (en) | 1997-05-07 | 1998-06-16 | Dravo Lime Company | Process for producing cement from a flue gas desulfurization process waste product |
| JPH10314758A (en) | 1997-05-19 | 1998-12-02 | Kubota Corp | Waste water treatment system for ceramic industry system waste water |
| GB9711439D0 (en) | 1997-06-04 | 1997-07-30 | Rogers Peter A | Bioreactor for dioxide management |
| US6110370A (en) | 1997-08-25 | 2000-08-29 | Water Research Commission | Treatment of water |
| KR100228748B1 (en) | 1997-10-10 | 1999-11-01 | 김충섭 | Method for producing methanol and dimethylether from carbondioxid |
| JPH11235999A (en) | 1998-02-20 | 1999-08-31 | Mitsubishi Heavy Ind Ltd | Carbon dioxide separation device |
| KR19980065026A (en) | 1998-06-17 | 1998-10-07 | 최세환 | Coal, Oil, Gas Combination Boiler |
| JP2000072981A (en) | 1998-08-28 | 2000-03-07 | Shimadzu Corp | Apparatus for producing carbon black by utilizing exhaust gas in cement production process |
| JP2000119049A (en) | 1998-10-13 | 2000-04-25 | Taiheiyo Cement Corp | Production of cement |
| JP3248514B2 (en) | 1998-10-29 | 2002-01-21 | 日本鋼管株式会社 | How to reduce carbon dioxide emissions |
| CA2255287A1 (en) | 1998-12-11 | 2000-06-11 | Rupesh N. Pandey | Carbon dioxide mitigation and utilization process via chemical fixation to valuable commodities |
| JP3543934B2 (en) | 1999-02-17 | 2004-07-21 | 三菱マテリアル株式会社 | How to recycle waste concrete |
| JP2000300983A (en) | 1999-04-20 | 2000-10-31 | Sekisui Chem Co Ltd | Carbon dioxide gas absorbent and its preparation |
| US6187277B1 (en) | 1999-06-04 | 2001-02-13 | Leon Kirschner | Method for purifying gases |
| JP3765690B2 (en) | 1999-07-28 | 2006-04-12 | 電気化学工業株式会社 | Low environmental load cement admixture and cement composition |
| US6258335B1 (en) | 1999-09-15 | 2001-07-10 | Sanjoy Kumar Bhattacharya | Conversion of carbon dioxide from ice exhausts by fixation |
| US6240859B1 (en) | 2000-05-05 | 2001-06-05 | Four Corners Group, Inc. | Cement, reduced-carbon ash and controlled mineral formation using sub- and supercritical high-velocity free-jet expansion into fuel-fired combustor fireballs |
-
2002
- 2002-04-12 AT AT02724060T patent/ATE368015T1/en not_active IP Right Cessation
- 2002-04-12 DE DE60221373T patent/DE60221373D1/en not_active Expired - Lifetime
- 2002-04-12 WO PCT/CA2002/000517 patent/WO2002083591A1/en active IP Right Grant
- 2002-04-12 EP EP02724060A patent/EP1377531B1/en not_active Expired - Lifetime
- 2002-04-12 CA CA002443222A patent/CA2443222C/en not_active Expired - Fee Related
- 2002-04-12 US US10/474,930 patent/US6908507B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| DE60221373D1 (en) | 2007-09-06 |
| EP1377531B1 (en) | 2007-07-25 |
| EP1377531A1 (en) | 2004-01-07 |
| CA2443222A1 (en) | 2002-10-24 |
| WO2002083591A1 (en) | 2002-10-24 |
| US20040129181A1 (en) | 2004-07-08 |
| ATE368015T1 (en) | 2007-08-15 |
| US6908507B2 (en) | 2005-06-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2443222C (en) | A process and a plant for the production of portland cement clinker | |
| JP3954009B2 (en) | Carbon dioxide immobilization method | |
| Mazzella et al. | CO2 uptake capacity of coal fly ash: Influence of pressure and temperature on direct gas-solid carbonation | |
| Viet et al. | The use of fly ashes from waste-to-energy processes as mineral CO2 sequesters and supplementary cementitious materials | |
| Pan et al. | An innovative approach to integrated carbon mineralization and waste utilization: A review | |
| Sanna et al. | Post-processing pathways in carbon capture and storage by mineral carbonation (CCSM) towards the introduction of carbon neutral materials | |
| TWI522163B (en) | Carbon dioxide sequestration involving two-salt-based thermolytic processes | |
| EP3656750A2 (en) | Use of carbon dioxide from and for cement | |
| Ghacham et al. | CO2 sequestration using waste concrete and anorthosite tailings by direct mineral carbonation in gas–solid–liquid and gas–solid routes | |
| CA2866186C (en) | Carbon dioxide chemical sequestration from industrial emissions by carbonation | |
| US7749476B2 (en) | Production of carbonate-containing compositions from material comprising metal silicates | |
| US20100313794A1 (en) | Production of carbonate-containing compositions from material comprising metal silicates | |
| KR20110061546A (en) | Production of carbonate-containing compositions from material comprising metal silicates | |
| JP2004261658A (en) | Method for absorbing/fixing carbon dioxide in combustion exhaust gas | |
| Mattila et al. | Production of precipitated calcium carbonate from steel converter slag and other calcium-containing industrial wastes and residues | |
| RU2596930C2 (en) | Reducing method for continuous extraction of calcium and producing precipitated calcium carbonate | |
| JP2015508332A (en) | Sequestration of carbon dioxide with pyrolysis process based on two kinds of salts | |
| Chang et al. | CO2 capture by using blended hydraulic slag cement via a slurry reactor | |
| Yoo et al. | Review of contemporary research on inorganic CO2 utilization via CO2 conversion into metal carbonate-based materials | |
| Ho et al. | Mineral carbonation using alkaline waste and byproducts to reduce CO2 emissions in Taiwan | |
| JP2023036636A (en) | Production of low-carbon footprint magnetic material | |
| Zaremba et al. | Properties of the wastes produced in the semi-dry FGD installation | |
| Wajima | Kinetics of the removal of hydrogen chloride gas using hydroxysodalite at high temperatures | |
| Anawar et al. | Biogeochemical Processes for Carbonation and Neutralization of Alkaline Mining Waste, Recycling and Waste Management | |
| Pan et al. | CO2 Mineralization and Utilization by a High-Gravity Carbonation Process: Past, Present, and Future |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20200831 |