Classifications

• • 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
  • C01F11/18—Carbonates
  • C01F11/181—Preparation of calcium carbonate by carbonation of aqueous solutions and characterised by control of the carbonation conditions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/24—Stationary reactors without moving elements inside
  • B01J19/245—Stationary reactors without moving elements inside placed in series
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
  • B01J8/20—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles with liquid as a fluidising medium
  • B01J8/22—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles with liquid as a fluidising medium gas being introduced into the liquid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/50—Carbon dioxide
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/60—Preparation of carbonates or bicarbonates in general
• • 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
  • C01F11/18—Carbonates
• • 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
  • C01F5/00—Compounds of magnesium
  • C01F5/24—Magnesium carbonates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2215/00—Auxiliary or complementary information in relation with mixing
  • B01F2215/04—Technical information in relation with mixing
  • B01F2215/0413—Numerical information
  • B01F2215/0436—Operational information
  • B01F2215/0468—Numerical pressure values
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2215/00—Auxiliary or complementary information in relation with mixing
  • B01F2215/04—Technical information in relation with mixing
  • B01F2215/0413—Numerical information
  • B01F2215/0436—Operational information
  • B01F2215/0472—Numerical temperature values
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2215/00—Auxiliary or complementary information in relation with mixing
  • B01F2215/04—Technical information in relation with mixing
  • B01F2215/0413—Numerical information
  • B01F2215/0436—Operational information
  • B01F2215/0481—Numerical speed values
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/27—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices
  • B01F27/271—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed radially between the surfaces of the rotor and the stator
  • B01F27/2711—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed radially between the surfaces of the rotor and the stator provided with intermeshing elements
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/01—Particle morphology depicted by an image
  • C01P2004/03—Particle morphology depicted by an image obtained by SEM
• • 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
  • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer

Definitions

• a method and apparatus to produce precipitated calcium carbonate consist of a method and an apparatus to produce precipitated calcium carbonate (PCC) or a composite of it with some another material in a continuous process.
• PCC precipitated calcium carbonate
• carbonation takes place by mixing calcium hydroxide and carbon dioxide gas in a pressurized reactor. Both of these are dissolved into water phase, in which the crystallization takes place.
• Precipitated calcium carbonate has been used for centuries among others in paper industry, but the share of it among paper minerals started to increase significantly only in 1990's.
• Today PCC is used worldwide in paper industry about 6 million tons yearly.
• All the traditional paper minerals are produced either by grinding and/or classification, which means that impact in particle size, size distribution and morphology is only limited.
• kaolin is just taken out from the ground, suspended to water and then purified from side stones and impurities with different classification processes. Finally the purified kaolin is classified to fractions such that the fine end is used for paper coating and the coarse end for paper filling.
• Ground calcium carbonate is according to its name ground lime stone. It is not possible to influence on particle shape in this process, but of course particle size can be decreased by increasing grinding. On the other hand grinding energy need increases exponentially along with the particle size, i.e. the finer particles one want to make, the more grinding energy is needed. Particle size distribution can be influenced by coarse material circulation after grinding, which means that after grinding this material is classified and the coarse end is circulated back to grinding and the fine end is collected as product. In practice one has to dilute the material for classification, which means that the product has to be thickened after classification, which inevitably increases production costs.
• PCC PCC to GCC
• the disadvantage of PCC to GCC is the higher production costs.
• the essential cost factor in PCC production is the lime burning, where calcium carbonate is broken down to calcium oxide and carbon dioxide in about 1000 0 C:
• PCC production takes place continuous way in a very small reaction chamber and 100 % conversion of the reaction is reached in a surprisingly short time, « 5 seconds.
• a small reactor is easily pressurized up to 2 MPa, high shear speed and ultra sound are breaking down the CO 2 bubbles to micro bubbles. Together these factors improve mass transfer from gas phase to water phase, CO 2 solubility to water. The very same factors improve also mass transfer from solid phase to water phase, solubility of calcium hydroxide to water.
• Very small reactor size 50 liters in comparison to 6 x 60 m 3 ) naturally decreases investment and production costs.
• the CO 2 gas is broken down to micro bubbles with high shear speed and ultra sound, from which it under high pressure dissolves to water significantly faster than under atmospheric pressure and from bigger bubbles, i.e. mass transfer from gas phase to water phase is dramatically increased.
• the pressure of the reaction chamber is typically 0,3 - 2,0 MPa, but is not limited to this.
• the circumferential velocity of the rotor of the reactor is more than 50 m/s, which is high enough to produce together with the holes and/or slits in the stator and rotor ultra sound, which effectively break down the CO 2 bubbles.
• Calcium hydroxide flow (1) is adjusted such that 100 % conversion is achieved with one run through the "Cavitron".
• another "Cavitron” is arranged in series with the first one or there is a post carbonation vessel (7) to secure the 100 % conversion.
• Carbon dioxide can be diluted by air, nitrogen or some another inert gas (8), which of course means that the speed of carbonation will slow down and additionally also the pressure of the gas combination has to be increased to compensate the counter pressure, which means that one has to use compressor to inject the gas to the system, the pressure of condensed carbon dioxide is enough as such.
• This alternative illustrates the situation that one wants to use for example exhaust gas as a source of CO 2 .
• the best source of CO 2 for this technology is condensed carbon dioxide.
• bio fuel production there will be significant amounts of high pressure carbon dioxide gases available, which could be used in PCC production as such. For example the bio diesel production will generate up to 300 000 tons CO 2 per each 150 000 ton of bio fuel.
• FIG 2 there is a picture of the stator and rotor of the reaction chamber.
• the rotation speed of the device used in this work is 12 000 1/min, which gives circumferential velocity of about 50 m/s.
• the rings (9) of the rotor and stator are overlapping such that the suspension of calcium carbonate is flowing through the slits or holes of the rings or between the rings.
• the gap between the rings is about 0.5 mm, but it is not limited to this dimension, it can be higher or lower.
• the flow is pulsating, because the channels through the rings are open only when the holes or slits are in the same position. Because of this and high circumferential velocity the device generates ultra sound effect.
• the material is flowing also between the rings, which gives high shear speed.
• the volume of the reaction chamber of this device is only about 50 ml. By increasing this volume one can increase the productivity of the reactor. This can be done by increasing the diameter of the reactor, which means that the rotation speed of it can be decreased to keep the circumfer
• FIG 3 there is a picture of the laboratory unit to produce PCC continuously. Already with this little device one can produce PCC 300 kg per day. With a reactor having 50 I reaction chamber one can produce same amount, about 100 000 t/a, as a commercial on site PCC plant. In a conventional plant like that about 3 - 5 batch reactors are needed, about 50 m 3 each, to produce the same amount.
• the target of this innovation is to reduce investment and production costs of PCC by utilizing the foreseeable supply of condensed carbon dioxide form power pants and high pressure gas from bio fuel production.
• This target is reached by using instead of conventional batch reactor a continuous reactor and by considerably speeding up the carbonation process, which is done by having an effect of high shear speed, typically > 20 000 1/s, high pressure and ultra sound on calcium hydroxide (solid phase), on carbon dioxide (gas phase) and on water (liquid phase).
• Continuous and extremely fast carbonation decreases the size of reactors, piping, pumps and all the other process devices. Condensed and/or high pressure carbon dioxide gas eliminates the need of compressors use. These altogether reduce investments and production costs of a plant
• the method of making PCC in the patent application WO9936361 Al is essentially the same as in the patent Fl 105179 B, i.e. the calcium hydroxide suspension is dispersed into gas phase.
• the target though is not fast carbonation but powder PCC. Therefore this method uses high volume of gas.
• the weaknesses of this method are the same as in the paten Fl 105179 B.
• the method of PCC carbonation in patent application WO2006005793 A1 is also essentially the same as in patent Fl 105179 B and therefore the weaknesses are the same.
• the target is to make nano size PCC by selecting optimal carbonation temperature.
• PCC crystals that are produced according to the method described in this application.
• the crystals are relatively big rhombohedral discrete or agglomerated particles, which are perhaps not ideal for paper making, but particle size and shape can be significantly changed with the reaction conditions as can be seen later on.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Nanotechnology (AREA)
• Physics & Mathematics (AREA)
• Composite Materials (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Combustion & Propulsion (AREA)
• Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

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• 2007
  • 2007-12-14 FI FI20070983A patent/FI121232B/fi not_active IP Right Cessation
• 2008
  • 2008-12-12 EP EP08867273A patent/EP2238077A4/de not_active Withdrawn
  • 2008-12-12 WO PCT/FI2008/000142 patent/WO2009083633A1/en active Application Filing

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