WO2017220161A1 - Composition de chaux pulvérulente hautement poreuse - Google Patents

Composition de chaux pulvérulente hautement poreuse Download PDF

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Publication number
WO2017220161A1
WO2017220161A1 PCT/EP2016/064701 EP2016064701W WO2017220161A1 WO 2017220161 A1 WO2017220161 A1 WO 2017220161A1 EP 2016064701 W EP2016064701 W EP 2016064701W WO 2017220161 A1 WO2017220161 A1 WO 2017220161A1
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WIPO (PCT)
Prior art keywords
equal
slaked lime
weight
composition
powdery slaked
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PCT/EP2016/064701
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English (en)
Inventor
Marion Lorgouilloux
Original Assignee
S.A. Lhoist Recherche Et Developpement
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Filing date
Publication date
Application filed by S.A. Lhoist Recherche Et Developpement filed Critical S.A. Lhoist Recherche Et Developpement
Priority to PCT/EP2016/064701 priority Critical patent/WO2017220161A1/fr
Priority to FR1755780A priority patent/FR3053038A1/fr
Priority to TW106121169A priority patent/TWI725204B/zh
Priority to DE202017007386.2U priority patent/DE202017007386U1/de
Priority to US16/309,561 priority patent/US11185841B2/en
Priority to MYPI2018002536A priority patent/MY190651A/en
Priority to PCT/EP2017/065528 priority patent/WO2017220775A1/fr
Priority to BR112018076011-0A priority patent/BR112018076011B1/pt
Priority to EP17732132.0A priority patent/EP3475228A1/fr
Publication of WO2017220161A1 publication Critical patent/WO2017220161A1/fr
Priority to CL2018003587A priority patent/CL2018003587A1/es

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F11/00—Compounds of calcium, strontium, or barium
    • C01F11/02—Oxides or hydroxides
    • 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
    • C04B2/00—Lime, magnesia or dolomite
    • C04B2/02—Lime
    • C04B2/04—Slaking
    • C04B2/045—After-treatment of slaked lime
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/51—Particles with a specific particle size distribution
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/14—Pore volume
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/20—Powder free flowing behaviour
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/80—Compositional purity

Definitions

  • the present invention relates to a powdery slaked lime composition having a BET specific surface area obtained from nitrogen adsorption equal to or greater than 25 m 2 /g and a total BJH pore volume consisting of pores with a diameter lower than 1000 A equal to or greater than 0.15 cm 3 /g.
  • Calcium oxide, CaO is often referred to as “quicklime”, while calcium hydroxide, Ca(OH) 2 , is referred to as “hydrated lime” or “slaked lime”, both sometimes being informally referred to as “lime”.
  • lime is an industrial product, based on calcium oxide or hydroxide, respectively.
  • quicklime it is meant a mineral solid material for which the chemical composition is mainly calcium oxide, CaO.
  • Quicklime is usually obtained by calcination of limestone (mainly CaC0 3 ).
  • Quicklime may also contain impurities, such as magnesium oxide, MgO, sulphur oxide, S0 3 , silica, Si0 2 or even alumina, Al 2 0 3 ,..., the sum of which being at a level of some weight %.
  • the impurities are expressed herein under their oxide form, but of course, they might appear under different phases.
  • Quicklime contains generally also some weight % of residual limestone, called unburned residues.
  • the quicklime suitable according to the present invention may comprise MgO, expressed under MgO form, at an amount comprised in the range of 0.5 to 10 weight %, preferably equal to or lower than 5 weight %, more preferably equal to or lower than 3 weight %, most preferably equal to or lower than 1 weight % with respect to the total weight of the quicklime.
  • quicklime is provided in the presence of water.
  • Calcium oxide in the quicklime reacts quickly with water to form calcium di- hydroxide Ca(OH) 2 , in the form of slaked lime or hydrated lime, in a reaction called hydration or slaking reaction which is very exothermic.
  • calcium di- hydroxide will be simply called calcium hydroxide.
  • the slaked lime may therefore contain the same impurities than those of the quicklime from which it is produced.
  • Slaked lime may also comprise Mg(OH) 2 at an amount comprised in the range of 0.5 to 10 weight %, preferably equal to or lower than 5 weight %, more preferably equal to or lower than 3 weight %, most preferably equal to or lower than 1 weight % with respect to the total weight of the slaked lime.
  • the slaked lime may also comprise calcium oxide, which might not have been entirely hydrated during the slaking step, or calcium carbonate CaC0 3 .
  • the calcium carbonate can be originated from the original limestone (unburned) from which said slaked lime is obtained (via calcium oxide) or being the result of a partial carbonation reaction of slaked lime through the contact with an atmosphere containing C0 2 .
  • the amount of calcium oxide in the slaked lime according to the present invention is typically equal to or lower than 3 weight %, preferably equal to or lower than 2 weight % and more preferably equal to or lower than 1 weight % with respect to the total weight of the slaked lime.
  • the amount of C0 2 in the slaked lime (mainly under the form of CaC0 3 ) according to the present invention is equal to or lower than 5 weight %, preferably equal to or lower than 3 weight %, more preferably equal to or lower than 2 weight %, with respect to the total weight of the slaked lime according to the present invention.
  • the slaking reaction is commonly performed in a hydrator, in which quicklime is fed upstream of the slaking direction, meaning the direction along which lime is transported along and into the hydrator. Slaked lime is withdrawn downstream the slaking direction.
  • Transportation means such as a horizontal shaft provided with mixing paddles for example, allow the transportation of lime along the slaking direction into the hydrator, from the quicklime feeding until the slaked lime withdrawal.
  • the transportation means allow also homogeneous mixture of lime undergoing hydration and therefore improves the contact between water and lime into the hydrator and avoids the formation of hot spots.
  • the residence time of the lime in the hydrator the water reactivity of the quicklime, the location of both the quicklime and of the water feeding along the hydrator, but also the amount of water with respect to the lime amount.
  • the water reactivity of quicklime is generally characterized and measured by the procedure given in the European standard EN459-2 and is often quantified by the value t 60i being the necessary time to reach a temperature of 60°C for a water volume of 600 cm 3 initially at 20°C, with the addition of 150 g of quicklime.
  • Slaked lime compositions are commonly industrially obtained through different processes depending on the amount of water with respect to the lime used.
  • the resulting slaked lime product is a standard slaked lime composition in a powdery state presenting a BET specific surface area typically between 12 and 20 m 2 /g and comprising generally less than 2 weight %, even less than 1.5 weight % of moisture (free water).
  • Standard slaked limes have many practical uses in a lot of industrial applications like water treatment, sludge conditioning, flue gas cleaning, agriculture, construction, etc.
  • the properties of the slaked lime are particularly critical for achieving good performance.
  • lime is used as a sorbent of several gaseous pollutants such as HCI, HF, SO x , IMO x .
  • the capture of these pollutants may be carried out under dry conditions and is then called "dry sorbent injection”.
  • This process consists of injecting powdery sorbents, such as powdery slaked lime, directly in the flow of flue gases or through a filter comprising a bed of fixed solid particles.
  • Another method for producing slaked lime with high specific surface area consists of slaking quicklime with an excess of water so as to obtain, at the exit of the hydrator, a wet slaked lime composition presenting a residual moisture content between 15 and 35 weight %.
  • the wet slaked lime composition is then further dried in a dryer device in order to reduce the moisture content and to form a dried powdery slaked lime composition.
  • Such method is generally called "semi wet process” and is notably disclosed in documents WO 97/14650 and US2894820.
  • the resulting powdery slaked lime composition consists essentially of dried calcium hydroxide particles having a residual moisture content of less than 2 weight % of the total composition, a high specific surface area (greater than 30 m 2 /g) together with a high pore volume (total nitrogen desorption pore volume of at least 0.1 cm 3 /g for pores with a diameter less than 1000 Angstroms).
  • This lime composition further presents an Alpine flowability comprised between 40 and 50% and is disclosed as providing excellent performance for the cleaning of flue gas in installations comprising a bag filter.
  • the powdery slaked lime composition is handled and transported, notably by screws or by air in ducts where the particles are distributed in the gas phase. Subsequently, the powdery slaked lime composition is commonly stored in the compressed state, for example in silos.
  • Clogging phenomena is a recurring problem of slaked lime composition during the manufacturing process, storage and further use as sorbent, especially with slaked lime composition presenting small particle size.
  • clogging phenomena clogging and sticking phenomena during the manufacturing process but also during the storage, the transportation or the further use of the powdery slaked lime composition.
  • powdery slaked lime compositions tend to stick on the walls of the container and are thereafter difficult to remove from these walls leading therefore to the loss of a non-negligible quantity of product.
  • the application of the powdery slaked lime composition is compromised due to blockages which are difficult to remove.
  • powdery slaked lime compositions comprising smaller particles present an increased efficiency of the treatment. More precisely, the flue gas treatment is improved due to a better dispersion of the powdery composition in the gaseous phase (flue gas) and a quicker contact between the pollutants and the lime particles of the composition. Moreover, smaller particles present a higher external contact surface, increasing therefore the proportion of hydrated lime that will actually enter into contact with the pollutants to capture.
  • the powdery slaked lime composition according to the present invention intends to provide a solution to this need by providing a powdery slaked lime composition, as mentioned in the beginning, characterized in that the composition furthermore has an Alpine flowability greater than 50 %, in particular equal to or greater than 51%, preferably equal to or greater than 52 %, advantageously equal to or greater than 54 %, in particular equal to or greater than 55 %, said aforementioned composition comprising a first fraction of particles having a size of less than 32 ⁇ and a second fraction of particles of a size greater than 32 ⁇ , the second fraction being lower than 10 weight percent with respect to the total weight of the composition.
  • second fraction of particles of a size greater than 32 ⁇ will be also expressed as 32 in the rest of the specification for the fraction retained at 32 ⁇ .
  • flowability fluidite in French
  • fluidity it is meant in the present invention the ability of powder to flow freely, in a regular and even way as individual particles.
  • the flowability of the powdery slaked lime composition according to the present invention has been measured on an Alpine air jet sieve device.
  • This Alpine flowability characterises the static flowability of a powder and is determined by the speed of passage of the particles with a diameter of less than 90 microns through a sieve of 90 microns (170 mesh) through the action of a suction.
  • the Alpine flowability expressed in % corresponds to the ratio between the weight of the fraction of less than 90 microns which has passed through the sieve in 15 seconds (with a depression of 100 mm of manometric liquid of density 0.88) and the total weight of the fraction of less than 90 microns which has passed through the sieve after 2 minutes (with a depression of 150 mm of manometric liquid of density 0.88).
  • the behavior of a powder into a storage silo can be simulated with another method using a powder rheometer such as a Brookfield Powder Flow Tester (PFT) according to the standard ASTM D6128.
  • a powder rheometer such as a Brookfield Powder Flow Tester (PFT) according to the standard ASTM D6128.
  • PFT Brookfield Powder Flow Tester
  • a powdery sample introduced in the equipment is subjected to increasing compaction overtime.
  • a specific torque is applied to the powder until failure (unconfined failure stress).
  • the response of the powder to the applied stress is recorded by a computer, which evaluates the static cohesiveness of the tested sample.
  • the results are expressed with a curve, which is compared to ASTM references.
  • the powdery slaked lime composition of the invention is also characterized by a dynamic flowability which can be measured by a Granudrum.
  • a quantity of the powdery material is placed into a drum having transparent windows, which is rotated and accelerated stepwise from 0 to 20 rpm, than stepwise decelerated.
  • the shape of the rotating powder heap (air/powder interface) inside the drum is analyzed by an algorithm.
  • a dynamic flow angle and a dynamic cohesiveness index are determined for each rotation speed.
  • the flowability of a powder is, amongst other, governed by the size of the particles composing this powder (see article "Flow properties of powders and bulks solids", Dietmar Schulze http://dietmar-schulze.de/grdlel.pdf).
  • the flowability of a powder generally decreases when the size (for example the diameter) of the particles composing the powder decreases.
  • the size of the particles composing the powdery slaked lime composition depends on different parameters.
  • the first parameter influencing the size of the particles is the particle size of the starting quicklime being used to form the slaked lime. Furthermore, the speed of the hydration reaction and the temperature inside the hydrator are also key factors governing the hydration reaction and therefore the size of the particles composing the final powdery slaked lime composition.
  • the flowability of the powdery slaked lime composition depends on multiple parameters some of which are difficult to control.
  • the flowability of the powder is an essential parameter characterizing a powder composition since a non-flowable powder may lead to clogging phenomena during the manufacturing process and during the storage of the powder but also during the further use of this powder.
  • the slaked lime may be treated in dryer and crusher devices that could notably influence the size distribution but also the shape of the particles of the powdery slaked lime and consequently influence the flowability of the powder.
  • the inner structure of the powdery slaked lime might also be modified and therefore, the drying step could also modify the porosity features of the powder.
  • the powdery slaked lime composition of the present invention keeps excellent sorption properties due to high porosity, namely a BET specific surface area obtained from nitrogen adsorption equal to or greater than 25 m 2 /g and a total BJH pore volume equal to or greater than 0.15 cm 3 /g.
  • the sorption properties of the powdery slaked lime composition according to the present invention are further improved by the particle size distribution of the composition characterized by a f1 ⁇ 2 lower than 10 weight % with respect to the total weight of the composition.
  • the efficiency of the treatment is improved due to a better dispersion of the powdery slaked lime composition in the gaseous phase (flue gas) and a quicker contact between pollutants and the lime particles of the composition according to the present invention.
  • smaller particles present higher external contact surface, increasing therefore the proportion of hydrated lime that will actually enter into contact with the pollutants to capture.
  • a highly porous powdery slaked lime composition composed of particles having a size of less than 32 ⁇ , with a i1 ⁇ 2 less than 10 weight % with respect to the total weight of the composition, can present an improved flowability.
  • the powdery slaked lime composition according to the present invention in addition to its very good sorption properties, presents a high flowability meaning that the powder is easier to handle, to transport, to store and consequently clogging or blockage phenomena are drastically reduced during the manufacturing process or the further use, reducing therefore costs caused by maintenance problems in the manufacturing installation or during its further use.
  • Another advantage of the powder according to the present invention is the reduction of the loss of product caused by the fact that the powder may stick on inner walls in the manufacturing process, during storage, transportation and during further use.
  • the increase of the flowability of the powder according to the present invention allows avoiding or at least reducing these sticking phenomena.
  • the powdery slaked lime composition according to the present invention comprises particles having a BET specific surface area obtained from nitrogen adsorption equal to or greater than 30 m z /g, preferably equal to or greater than 32 m 2 /g, advantageously equal to or greater than 35 m 2 /g.
  • the powdery slaked lime composition has a BET specific surface area obtained from nitrogen adsorption equal to or lower than 50 m 2 /g, in particular equal to or lower than 48 m 2 /g.
  • BET specific surface area it is meant in the meaning of the present specification the specific surface area measured by manometry with adsorption of nitrogen at 77 K after degassing under vacuum at a temperature comprised between 150 and 250°C, notably at 190°C for at least 2 hours and calculated according to the multipoint BET method as described in the ISO 9277:2010E standard.
  • the powdery slaked lime composition according to the present invention has a total BJH pore volume consisting of pores with a diameter lower than 1000 A, obtained from nitrogen desorption, equal to or greater than 0.17 cm 3 /g, particularly higher than or equal to 0.18 cm 3 /g, preferably equal to or greater than 0.19 cm 3 /g, in particular equal to or greater than 0.20 cm 3 /g, advantageously equal to or greater than 0.21 cm 3 /g.
  • the powdery slaked lime composition of the invention has, advantageously, a total BJH pore volume consisting of pores with a diameter lower than 1000 A, obtained from nitrogen desorption, equal to or lower than 0.30 cm 3 /g, in particular lower than 0.28 cm 3 /g.
  • the powdery slaked lime composition according to the invention has a BJH pore volume consisting of pores with a diameter ranging from 100 to 300 A, obtained from nitrogen desorption, equal to or greater than 0.07 cm 3 /g, preferably equal to or greater than 0.10 cm 3 /g, advantageously equal to or greater than 0.11 cm 3 /g, in particular equal to or greater than 0.12 cm 3 /g and typically lower than 0.15 cm 3 /g, in particular lower than 0.14 cm 3 /g.
  • the powdery slaked lime composition according to the present invention has a BJH pore volume consisting of pores with a diameter ranging from 100 to 400 A, obtained from nitrogen desorption, equal to or greater than 0.09 cm 3 /g, preferably equal to or greater than 0.12 cm 3 /g, advantageously equal to or greater than 0.13 cm 3 /g, in particular equal to or greater than 0.14 cm 3 /g and typically lower than 0.17 cm 3 /g, in particular lower than 0.16 cm 3 /g.
  • BJH pore volume the pore volume as measured by manometry with adsorption of nitrogen at 77 K after degassing under vacuum at a temperature comprised between 150 and 250°C, notably at 190°C for at least 2 hours and calculated according to the BJH method, using the desorption curve, with the hypothesis of a cylindrical pore geometry.
  • total pore volume in the present specification, it is meant the BJH pore volume consisting of pores with a diameter smaller than or equal to 1000 A.
  • the powdery slaked lime composition according to the present invention further presents a mean particle size d 50 equal to or lower than 8 ⁇ , preferably equal to or lower than 6 ⁇ , advantageously equal to or lower than 4 ⁇ .
  • the notation d x represents a diameter expressed in ⁇ , measured by laser granuiometry in methanol after sonication, relatively to which X % by volume of the measured particles are smaller or equal.
  • the powdery slaked lime composition according to the present invention presents a non-solid residual phase content.
  • said non-solid residual phase comprises water and/or residual additives (mineral and/or organic), free or linked to the lime compound.
  • non-solid residual phase content of the slaked lime composition it is meant the proportion of non-solid residual phase of the slaked lime composition (i.e. the water content, such as the free water content, and/or the content of residual additives from the manufacturing process of the said slaked lime composition, meaning originated from additives added before, during or after the slaking of quicklime) determined by a loss on ignition test.
  • the loss on ignition test consists of heating, at atmospheric pressure, around 20 g of the powdery slaked lime composition at a predetermined temperature, namely 110 °C or 180 °C, and measuring the weight over time of the powdery composition by means of a thermal balance until the weight of the powder does not vary of more than 2 mg during at least 20 seconds.
  • a predetermined temperature namely 110 °C or 180 °C
  • the non-solid residual phase therefore contents all non-solid components, notably liquid components, having together an evaporation temperature lower than that applied, which will then leave the slaked lime composition during the heating process at the predetermined temperature.
  • the weight % of the non-solid residual phase and of the remaining solid, called the dry extract are both calculated based on the weight of the product before ignition and after ignition and both expressed with respect to the weight of the product before the ignition test. The loss on ignition result may therefore vary depending on the temperature used during the test.
  • it may be higher at 180 °C than at 110 °C if additives are used during the slaking process or after, and if such additives or their derived phases present an evaporation point higher than 110 °C and lower than 180 °C, or form with the free water an azeotropic substance or an aqueous mixture that evaporates between those temperatures.
  • the non-soiid residual phase content of the powdery slaked lime composition according to the present invention can be measured through a loss on ignition test at 180 °C.
  • the loss on ignition result is equal to or higher than 0.3 weight %, preferably equal to or higher than 0.5 weight %, and equal to or smaller than 5 weight %, preferably equal to or smaller than 4.5 weight %, in particular equal to or smaller than 4 weight %, and represents the quantity of water and/or substances contained therein having an evaporation point less than or equal to 180 °C.
  • the non-solid residual phase content of the powdery slaked lime composition according to the present invention can be further measured through a loss on ignition test at 110 °C.
  • the loss on ignition value is equal to or smaller than 3.5 weight %, preferably equal to or smaller than 3 weight %, advantageously equal to or smaller than 2.5 weight %, in particular equal to or smaller than 2 weight %, notably equal to or smaller than 1.5 weight % and higher than 0 weight %, preferably equal to or higher than 0.2 weight %, advantageously equal to or higher than 0.3 weight %, in particular equal to or higher than 0.5 weight % and represents mainly the quantity of water and/or volatile substances contained therein having an evaporation point less than or equal to 110 °C, in particular water.
  • the powdery slaked lime composition according to the invention further presents an alkali phase characterized by an alkali metal content that is equal to or greater than 0.2 weight % and equal to or less than 3.5 weight % with respect to the total weight of the powdery slaked lime composition.
  • the alkali phase may be under the ionic form or under a binded form.
  • Different kind of salts can be added before, during and/or after the slaking process, in particular alkali metal compound selected from the group consisting of alkali metal hydroxides, carbonates, hydrogencarbonates, nitrates, phosphates, persulphates and monocarboxylates, such as alkali metal acetates or formiates, and mixtures thereof, in particular those of sodium, potassium and/or lithium.
  • the powdery slaked lime composition according to the present invention further contains residual mineral solid additives and/or organic solid additives.
  • the residual organic solid additives may originated from organic additives added before, during and/or after the slaking process and selected in the group of (mono-) or (poly-)ethylene glycol and (mono-) or (poly-)ethanolamine, in particular triethylene glycol, triethanolamine, and calcium stearate and their mixtures.
  • the particles of the powdery slaked lime composition of the present invention are mainly composed of hydrated lime, also known as slaked lime, resulting from the treatment of quicklime with water to thereby convert the oxides into hydroxides.
  • the hydrated lime of the present invention can be high calcium or dolomitic hydrated lime.
  • the powdery slaked lime composition of the present invention may contain the same impurities than those of the quicklime from which it is produced, such as magnesium oxide, gO, sulphur oxide, S0 3 , silica, Si0 2 or even alumina, Al 2 0 3 ,..., the sum of which being at a level of some weight %.
  • the impurities are expressed herein under their oxide form, but of course, they might appear under different phases.
  • the slaked lime according to the present invention may comprise magnesium under the form of MgO and/or Mg(OH) 2 , at an amount comprised in the range of 0.5 to 10 weight %, preferably equal to or lower than 5 weight %, more preferably equal to or lower than 3 weight %, most preferably equal to or lower than 1 weight % expressed under the oxide form, with respect to the total weight of the slaked lime composition.
  • the slaked lime may also comprise calcium oxide, which might not have been entirely hydrated during the slaking step, or calcium carbonate CaC0 3 .
  • the calcium carbonate can be originated from the original limestone (unburned) from which said slaked lime is obtained (via calcium oxide) or being the result of a partial carbonation reaction of slaked lime through the contact with an atmosphere containing C0 2 .
  • the amount of calcium oxide in the slaked lime according to the present invention is typically equal to or lower than 3 weight %, preferably equal to or lower than 2 weight % and more preferably equal to or lower than 1 weight % with respect to the total weight of the slaked lime.
  • the amount of C0 2 in the slaked lime (mainly under the form of CaC0 3 ) according to the present invention is typically equal to or lower than 5 weight %, preferably equal to or lower than 3 weight %, more preferably equal to or lower than 2 weight %, with respect to the total weight of the slaked lime according to the present invention.
  • the amount of available lime present in the powdery slaked lime composition according to the present invention is equal to or greater than 85 weight %, preferably equal to or greater than 87 weight %, preferentially equal to or greater than 90 weight %, advantageously equal to or greater than 92 weight %, and even equal to or greater than 95 weight % with respect to the dry content of the slaked lime composition after LOI at 180°C.
  • the remaining weight % of the slaked lime composition are mainly made of limestone-origin compounds and of residues originating from the non-solid residual phase.
  • the available lime content present in the powdery slaked lime composition is determined by putting 0.5 g of the powdery slaked lime composition into a sugar solution (15g of sugar in 150 cm 3 of deionized water). The sugar solution will dissolve the available lime (i.e. the calcium oxide and/or calcium hydroxide) contained in the sample.
  • the resulting mixture is agitated during at least 10-15 minutes to insure complete dissolution and then titrated with a solution of hydrochloric acid (HCI 0.5N), phenolphthalein being used as indicator.
  • HCI 0.5N hydrochloric acid
  • the Ca concentration measured by this titration is then expressed as Ca(OH) 2 .
  • the invention relates also to an industrial sorbent composition comprising at least said powdery slaked lime composition according to the invention.
  • the invention relates also to the use of the powdery slaked lime composition according to the present invention for purifying flue gases.
  • the powdery slaked lime composition according to the present invention is used in a dry sorbent injection.
  • the powdery slaked lime composition according to the present invention is used for capturing acidic pollutants from flue gases, such as HCI, HF, SO x , NO x ,...
  • the powdery slaked lime composition according to the present invention is used in an industrial sorbent composition, for example in combination with at least one other sorbent typically known for treating flue gas such as a sorbent selected among the list of organic compounds, in particular activated carbon, lignite coke and mixture thereof, and mineral compounds, in particular mineral compounds known for capturing dioxins, furans and/or heavy metals, such as halloysite, sepiolite, bentonite or any sorbent disclosed in the application DE4034417.
  • a sorbent selected among the list of organic compounds, in particular activated carbon, lignite coke and mixture thereof
  • mineral compounds in particular mineral compounds known for capturing dioxins, furans and/or heavy metals, such as halloysite, sepiolite, bentonite or any sorbent disclosed in the application DE4034417.
  • the powdery slaked lime composition according to the present invention can notably be produced, while not being limited thereto, by a process comprising the steps of :
  • drying and crushing said slaked lime to form the powdery slaked lime composition is characterized in that the drying and crushing steps are simultaneously performed and are a single fluidification step of the slaked lime for forming a powdery slaked lime composition having an Alpine flowability greater than 50% and are performed in a dryer-crusher chosen in the group consisting of a pin mill dryer, a cage mill dryer, a flash dryer de-agglomerator and the combination thereof until the powdery slaked lime composition comprises a first fraction of particles having a size of less than 32 ⁇ and a second fraction of particles of a size greater than 32 ⁇ , the second fraction being lower than 10 weight % with respect to the total weight of the composition.
  • flash dryer de-agglomerator it is meant a flash dryer in which there is a rotor or rotating paddles at the bottom of the drying chamber that fluidizes the product and creates turbulences in the hot air flow that is entering the drying chamber tangentially. By doing so, the wet (agglomerated) slaked lime is rapidly dispersed and disintegrated into fine dried particles. The resulting fine particles exit the drying chamber from its top whereas larger particles remain in the chamber for further drying and de-agglomeration.
  • flash dryer de-agglomerator examples include notably the Anhydro Spin Flash Dryer ® commercialized by SPX FLOW, the Drymeister ® Flash Dryer commercialized by Hosokawa Micron Group or the Swirl fluidizerTM commercialized by GEA Group.
  • the drying-crushing steps are performed until the powdery slaked lime composition presents a mean particle size d 50 equal to or lower than 8 ⁇ , advantageously equal to or lower than 6 ⁇ , in particular equal to or lower than 4 ⁇ .
  • the drying-crushing steps are performed until the powdery slaked lime composition presents a non-solid residual phase content, measured by a loss on ignition test at 180°C, equal to or less than 5 weight %, preferably equal to or less than 4.5 weight %, in particular equal to or less than 4 weight %, and equal to or higher than 0.3 weight %, preferably equal to or higher than 0.5 weight %, with respect to the total weight of the powdery slaked lime composition.
  • a fine and highly porous powdery slaked lime composition according to the present invention is produced industrially by mixing water and quicklime (2.7 t/h of quicklime) in an hydrator, in such amounts that the product comes out of the hydrator with a non-solid residual phase content, measured by a loss on ignition test (LOI) at 180°C, ranging between 22 and 24 wt%.
  • LOI loss on ignition test
  • 0.2 % of diethylene glycol (expressed as % of the quicklime weight) is added in the slaking water prior to hydration.
  • the wet slaked lime coming out of the hydrator is then transported to a pin mill in which some hot air is injected so as to flash dry the wet slaked lime and produce the highly porous powdery slaked lime composition before storing it in a storage area.
  • the resulting powdery slaked lime composition has an Alpine flowability of 51 %, a d 50 of 4.2 ⁇ and a fraction of particles of a size greater than 32 ⁇ (R 32 ) of 6.2 weight %. Its specific surface area and total pore volume are 41.1 m 2 /g and 0.214 cm 3 /g / respectively.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

Abstract

Une composition de chaux pulvérulente ayant une aptitude à l'écoulement alpin supérieure à 50 % et comprenant une première fraction de particules ayant une taille inférieure à 32 µm et une seconde fraction de particules ayant une taille supérieure à 32 µm, la seconde fraction ayant un poids inférieur à 10 % du poids total de la composition, et son procédé de fabrication.
PCT/EP2016/064701 2016-06-24 2016-06-24 Composition de chaux pulvérulente hautement poreuse WO2017220161A1 (fr)

Priority Applications (10)

Application Number Priority Date Filing Date Title
PCT/EP2016/064701 WO2017220161A1 (fr) 2016-06-24 2016-06-24 Composition de chaux pulvérulente hautement poreuse
FR1755780A FR3053038A1 (fr) 2016-06-24 2017-06-23 Composition de chaux eteinte pulverulents tres poreuse
TW106121169A TWI725204B (zh) 2016-06-24 2017-06-23 粉末熟石灰化合物及其應用
DE202017007386.2U DE202017007386U1 (de) 2016-06-24 2017-06-23 Hochporöse, pulverförmige Zusammensetzung aus gelöschtem Kalk
US16/309,561 US11185841B2 (en) 2016-06-24 2017-06-23 Highly porous powdered slaked lime composition
MYPI2018002536A MY190651A (en) 2016-06-24 2017-06-23 Highly porous powdered slaked lime composition
PCT/EP2017/065528 WO2017220775A1 (fr) 2016-06-24 2017-06-23 Composition de chaux éteinte pulvérulente très poreuse
BR112018076011-0A BR112018076011B1 (pt) 2016-06-24 2017-06-23 Composição de cal apagada pulverulenta extremamente porosa e seu uso e composição de sorvente industrial
EP17732132.0A EP3475228A1 (fr) 2016-06-24 2017-06-23 Composition de chaux éteinte pulvérulente très poreuse
CL2018003587A CL2018003587A1 (es) 2016-06-24 2018-12-13 Composición de cal apagada en polvo altamente porosa.

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10369518B2 (en) * 2017-03-17 2019-08-06 Graymont (Pa) Inc. Calcium hydroxide-containing compositions and associated systems and methods

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2894820A (en) 1953-01-02 1959-07-14 American Marietta Co Method of producing agglomerated lime hydrate
DE4034417A1 (de) 1990-10-29 1992-04-30 Walhalla Kalk Entwicklungs Und Hochreaktive reagentien und zusammensetzungen fuer die abgas- und abwasserreinigung, ihre herstellung und ihre verwendung
WO1992009528A1 (fr) 1990-11-21 1992-06-11 Lhoist Recherche Et Developpement S.A. Hydroxyde de calcium et/ou de magnesium, sa preparation et son utilisation
US5173279A (en) * 1990-11-21 1992-12-22 Lhoist Recherche Et Developpement S.A. Method and composition for treating flue or exhaust gases utilizing modified calcium hydroxide
US5223239A (en) * 1990-07-24 1993-06-29 Research Corporation Technologies, Inc. Method of preparing hydrated lime
WO1997014650A1 (fr) 1995-10-19 1997-04-24 Lhoist Recherche Et Developpement S.A. PARTICULES DE Ca(OH)¿2?
US20090246117A1 (en) * 2008-03-25 2009-10-01 Jean-Yves Tilquin Method of forming a hydrated lime for acid gas removal from flue gas

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2894820A (en) 1953-01-02 1959-07-14 American Marietta Co Method of producing agglomerated lime hydrate
US5223239A (en) * 1990-07-24 1993-06-29 Research Corporation Technologies, Inc. Method of preparing hydrated lime
US5492685A (en) 1990-07-24 1996-02-20 The Board Of Trustees Of The University Of Illinois High surface area hydrated lime and method of removing SO2 from a gas stream
DE4034417A1 (de) 1990-10-29 1992-04-30 Walhalla Kalk Entwicklungs Und Hochreaktive reagentien und zusammensetzungen fuer die abgas- und abwasserreinigung, ihre herstellung und ihre verwendung
WO1992009528A1 (fr) 1990-11-21 1992-06-11 Lhoist Recherche Et Developpement S.A. Hydroxyde de calcium et/ou de magnesium, sa preparation et son utilisation
US5173279A (en) * 1990-11-21 1992-12-22 Lhoist Recherche Et Developpement S.A. Method and composition for treating flue or exhaust gases utilizing modified calcium hydroxide
WO1997014650A1 (fr) 1995-10-19 1997-04-24 Lhoist Recherche Et Developpement S.A. PARTICULES DE Ca(OH)¿2?
US20090246117A1 (en) * 2008-03-25 2009-10-01 Jean-Yves Tilquin Method of forming a hydrated lime for acid gas removal from flue gas

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GELDART GELDART, D.; ABDULLAH, E. C.; VERLINDEN, A, CHARACTERISATION OF DRY POWDERS. POWDER TECHNOL, vol. 190, no. 1-2, 2009, pages 70 - 74

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10369518B2 (en) * 2017-03-17 2019-08-06 Graymont (Pa) Inc. Calcium hydroxide-containing compositions and associated systems and methods
US10610825B2 (en) 2017-03-17 2020-04-07 Graymont (Pa) Inc. Calcium hydroxide-containing compositions and associated systems and methods
US10874982B2 (en) 2017-03-17 2020-12-29 Graymont (Pa) Inc. Calcium hydroxide-containing compositions and associated systems and methods
US11344844B2 (en) 2017-03-17 2022-05-31 Graymont (Pa) Inc. Calcium hydroxide-containing compositions and associated systems and methods

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