WO2008059530A2 - Procédé amélioré d'acidification de l'argile - Google Patents

Procédé amélioré d'acidification de l'argile Download PDF

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Publication number
WO2008059530A2
WO2008059530A2 PCT/IN2007/000527 IN2007000527W WO2008059530A2 WO 2008059530 A2 WO2008059530 A2 WO 2008059530A2 IN 2007000527 W IN2007000527 W IN 2007000527W WO 2008059530 A2 WO2008059530 A2 WO 2008059530A2
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WIPO (PCT)
Prior art keywords
clay
smectite
acid
smectite clay
drying
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PCT/IN2007/000527
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English (en)
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WO2008059530A3 (fr
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Chetan Navnithlal Shah
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Chetan Navnithlal Shah
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Publication of WO2008059530A2 publication Critical patent/WO2008059530A2/fr
Publication of WO2008059530A3 publication Critical patent/WO2008059530A3/fr

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
    • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
    • C09C1/40—Compounds of aluminium
    • C09C1/42—Clays
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/20—Silicates
    • C01B33/36—Silicates having base-exchange properties but not having molecular sieve properties
    • C01B33/38—Layered base-exchange silicates, e.g. clays, micas or alkali metal silicates of kenyaite or magadiite type
    • C01B33/40—Clays
    • 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
    • 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

Definitions

  • the present invention relates to activated clay. Particularly, the present invention relates to a process for the smectite clay activation.
  • Smectite refers to a family of clays primarily composed of hydrated sodium calcium aluminum silicate. Common names for smectite include montmorillonite or sodium montmorillonite.
  • Attapulgite/Palygorskite Palygorskite (also known as attapulgite) is a magnesium aluminum silicate type of clay available in the states of Bengal, Andhra Pradesh and Bengal in India. It is one of the types of fuller's earth.
  • Kaolinite is a clay mineral with the chemical composition Al 2 Si 2 O 5 (OH) 4 . It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina. Rocks that are rich in kaolinite are known as china clay or kaolin.
  • Meta kaolinite the kaolinite clay heated to a temperature of 750 degree C for 3 hours forms Meta kaolin.
  • Total acidity The total acidity of a solution is a measure of all the hydrogen ions (H + ) of both the fixed and volatile acids present.
  • Methylene blue value This value indicates the cation exchange capacity of smectite clay. The value increases with the quantity of active clay in a composition.
  • Bromine index As per ASTM D1491. Bromine number signifies the presence of un-saturation or double bonds, or olefins in the hydrocarbon. These olefins interfere in the further processing and have to be removed. These olefins have approximately same boiling points as aromatic compounds and separation by means of distillation is not possible. Bromine Number is expressed as the grams of Bromine (Br) available to react with 100 grams of the product. Bromine Index is expressed as the milligrams of Bromine available to react with 100 grams of the product under the specified condition.
  • Naturally occurring clays are known to exhibit excellent adsorbing and decolorizing properties. These properties can further be enhanced by treating clay with a suitable mineral acid leading to clay activation.
  • the acid activation of clay is often accompanied by. a change in key physical properties of clay such as surface acidity, surface area, pore volume and the like.
  • clays may be acid treated to enhance their ability to decolorize oils.
  • bentonite clays particularly the non-water swelling bentonite clays such as calcium and magnesium bentonites.
  • acid activated bentonite clays are used for decolorizing or bleaching of various oils such as mineral oils, vegetable oils, various fractions from petroleum, especially lubricating oils, and the refining of used lubricating oils, and purification of melted animal fats and beeswax.
  • Bentonite is a native, colloidal, hydrated, mineral of the Dioctahedral Smectite Group that is primarily composed of the mineral montmorillonite, which has been processed to remove grit and non-swellable ore components.
  • Smectite refers to a family of clays primarily composed of hydrated sodium calcium aluminum silicate. Common names for smectite include montmorillonite or sodium montmorillonite.
  • Smectite is a clay mineral having a 2:1 expanding crystal lattice.
  • Smectite is used to slow the progress of water through soil or rocks; used in drilling mud to give the water greater viscosity; used to produce nanocomposites; used as an absorbent to purify and discolor liquids; used as filler in paper and rubber; and used as a base for cosmetics and medicines.
  • the reactive properties, of naturally occurring clays can be altered or enhanced by acid treatment/ activation or through organic modification.
  • Acid treatment disrupts the laminar structure of the clay and exposes the parts of interlayer surface to N 2 and other non-swelling adsorbates.
  • surface area increases after dissolution of soluble lattice ions gradually in octahedral sites. Due to the partial dissolution Of Al +3 , Mg +2 & Fe +3 ions the protons of the hydroxyl groups at the comers of the octahedron may become more labile as a result of structural deformation and increased acidity.
  • the organic modification of clay involves substitution of exchangeable cation in the interlayer structure of the clay. The nature and technique used in the modification of clay largely depends on the desired properties.
  • US Patent No 6602816 discloses acid treatment of clay. According to this process, the clay sample in granular form is contacted with an aqueous acid solution of mineral acid. The acid treatment process is carried out at a temperature of about 60-100 0 C for about 3-20 hours. The acid concentration is about 20-35% by mass. After the treatment, the mother liquor containing aluminum, magnesium, calcium and iron salts are recovered and the acid treated clay is washed with water, dried, classified to obtain the activated regular shaped clay particles as a finished product.
  • US Patent No. 5908500 discloses a method for preparing bleaching clay. This method comprises combining intercalating clay with mineral acid and organic polar liquid admixture. The slurry so formed is agitated for 1-3 minutes. Thereafter, the slurry is filtered through a Buckner filter to remove the polar organic liquid and air-dried at ambient temperature to yield bleaching clay.
  • Japanese Patent application No. JP 335/1948 discloses a method of producing activated clay. This process comprises kneading clay in water and molding into a desired particle size typically of 0.5-30 mm and introducing the resulting clay into an acid resistant container followed by heating and circulating an inorganic acid therein to activate the clay.
  • the clay is washed after acid treatment with water to remove excess acid and leached out salts of Mg ++ , Ca ++ and the like, adhered to the clay surface as a result of acid treatment. Removal of leached out heavy metal ions such as lead, mercury and the like is also important as the activated clay may also be used in treating edible oil and other sensitive material where contamination with heavy metal ions are undesirable.
  • Another object of the present invention is to provide a process with modified smectite clay.
  • Yet another object of the present invention is to provide a process which is environment-friendly.
  • Yet another object of the present invention is to provide a process which produces a product of enhanced clay activity.
  • Yet another object of the present invention is to provide a process which produces a product which generates less toluene.
  • Yet another object of the present invention is to provide a process which produces a product with high total acidity.
  • the present invention discloses a process for acid activation of smectite clay suitable for use in the treatment of hydrocarbons, said clay having superior catalytic activity, higher life and less cost.
  • a process for activating of smectite clay comprising the following steps: a. drying the smectite clay; b. cleaning the dried smectite clay and testing for hardness; segregating smectite clay less than 2 Mohs in batches for further treatment; c. checking the methylene blue value of each batch of the segregated clay and selecting batches with methylene blue value greater than 400 mg/g for further treatment; d. adjusting the clay moisture to 30 - 40% by addition of 12-15% sulfuric acid; e. extruding the moistened clay to a granular size of 12 to 15 mm; f.
  • drying of the smectite clay in step (a) is done by a process selected from a group of processes consisting of hot air drying, tray drying, furnace diying, rotary kiln drying and electric oven drying.
  • the hardness of the clay in step (b) is measured by the abrasive index method.
  • the process of extrusion is performed by first extruding the dried clay to a particle size of 20 - 30 mm and immediately re extruding to a particle size of 12 - 15 mm in the second extrusion.
  • the reactor in the step (f) is a fiber or ceramic glass lined reactor.
  • the total acidity is checked periodically in step (f), (g) and (i).
  • the granules in step (i) are particulated by a process selected from the group of processes consisting of hammer milling, rolling, sieving and vibrosifter.
  • the present invention provides a process for the production of activated clay by treating Smectite clay or composition thereof with mineral acid.
  • Smectite clay such as Ca-Montmorillonite is used for acid treatment.
  • many other clay types and mixtures thereof having different physical characteristics may also be advantageously used if desired.
  • the Smectite clay used in the preparation of catalyst of the present invention is Ca-Montmorillonite clay which has the following characteristics and specifications: SiO 2 : 46 to 54 %; Al 2 O 3 : 10 to 18 %; Fe 2 O 3 : 6.0 to 18 %; TiO 2 : 1.0 to 3.5 %; CaO: 1.2 to 3.0 %; MgO: 1.5 to 3.0 %; P 2 O 5 : 0.01 to 0.2 %; Na 2 O: 1.0 to 2.5%; K 2 O: 0.1 to 0.5 %; SO 3 : 0.1 to 0.3 %; LOI 9.5 to 13.5.
  • the lumps of smectite clay are dried in sunlight or by using any other type of drying or heating method. After drying, the lumps of clay are crushed to convert the lumps into smaller particles of .50-60 mm in diameter. After drying, the clay is cleaned manually to remove stones, particles with metallic iron material which are generally dark reddish brown and hence can be removed easily by color sorting. The dried and cleaned clay is tested for hardness testing by abrasive index method in batches. The batches with less than 2 Mohs hardness are selected for further treatment. This clay is analyzed for Methylene Blue value by titrating the clay solution (in tetra sodium pyrophosphate) with Methylene blue dye solution. The batches with methylene blue value greater than 400 of are selected for acid treatment which indicates that the clay has good resistance for deactivation. The clay is also subjected to chemical analysis.
  • the tested clay is mixed with 10-12 % dilute sulfuric acid is at room temperature.
  • the sulfuric acid used for the acid treatment is of about 98.5% purity.
  • the clay has a moisture content of 35-40 %.
  • Clay is extruded in an extruder to a diameter of 24 mm and was immediately re extruded to a diameter of 12mm size. Double extrusion was carried out to form stable extruders.
  • the sulfuric acid activated extrudates are conveyed to a reactor for second acid treatment.
  • the reactor used for second acid treatment is an acid resistant, ceramic glass or fiber lined reactor.
  • the granulated clay in the reactor is treated with continuously circulating sulfuric acid of 33 - 39% concentration at a temperature of 80 - 95 degree C till the total acidity exceeds 22 mg KOH/g and the acid containing salts of Mg and Ca is drained off from the reactor.
  • the acidity of the treated clay is periodically measured by withdrawing samples at fixed time intervals and the pH of solution is around 4-5.
  • the acid activated clay is washed with soft water (containing less than 18 ppm of Ca +"1" and Mg ++ ) at room temperature.
  • the washing of activated clay is done by accelerated water washing cycles for effective washing as well as retaining/fixing the acidity.
  • the water is circulated through the reactor from top to bottom direction.
  • the speed of water circulation through the reactor is about 150- 5000 lit/min.
  • 15 tons of the activated clay is washed using 35,000-42,000 liters of soft water.
  • the pump is switched off and the wash-water containing leached salts adhered or adsorbed on the clay surface is drained off.
  • the acidity of this washed clay is also estimated by titrating with KOH solution.
  • the acidity of water washed clay is about 22 mg KOH/g and pH of solution is about 4-5 and moisture content of the clay is about 60-70 %.
  • the wet clay is taken out and dried to a moisture level of 5% or below in an electric oven at a temperature of about 1 10 degree C.
  • the dried acid activated clay is pulverized gently in a hammer mill & sieved to size 0.25mm to 2 mm diameter 'and rolled in a vibrosifter.
  • the final acid activated product is checked for its total acidity and pH.
  • the activated smectite clay prepared according to process of the present invention is used in the treatment of aromatic hydrocarbon stream and is found to be very good.
  • Smectite clay was dried in sunlight and was crushed into lumps of 50 - 60 mm diameter in size and was cleaned manually.
  • the hardness of the clay was tested by abrasive index method in batches and hardness less than 2 Mohs was segregated for testing for methylene blue test.
  • the batches were tested for methylene blue value by mixing 0.5 gm of sample 4 with 4.5 gm of washed graded clay-free silica sand and 5 gm silicon carbide in a 250 ml conical flask, to this 100 ml of 2 % tetra sodium pyrophosphate solution was added. This solution was stirred on a magnetic stirring plate for 10 minutes.
  • the clay was extruded to a particle size of 20 - 30 mm in the first extrusion and immediately re extruding to a particle size of 12 - 15 mm in the second extrusion.
  • the granulated clay were subjected to acid activation in a reactor with continuously circulating sulfuric acid at a temperature of 87 degree C, where samples were tested periodically for total acidity and the circulation was continued till the total acidity exceeded 22 mg KOH/g acidity was checked by suspending 2 gm of the sample in 100 ml of 4 % NaCl solution & boiled at 95 0 C for 30 minutes & filtered. The filtrate was titrated with 0.05N KOH using Phenolpthalein as indicator.
  • Total acidity was measured as mg KOH/ 100 gm of the sample and found to be 25 mg KOH/g.
  • the total acidity of smectite clay was checked by titrating with KOH solution and the acid was drained off the reactor.
  • the acid-treated product was washed rapidly with water by circulating the washing water in a reactor at a speed of 166.6 Lit/min.
  • the acidity of the washed clay was also checked and found to be 23 mg KOH/g with a pH of 3.0 and the moisture content of 60 - 70%.
  • the washed wet clay was dried in an electric oven at a temperature of 110 degree C.
  • Example 2 The dried acid activated clay was pulverized gently in a hammer mill & sieved to size 0.25mm to 2 mm diameter and rolled in a vibrosifter. The obtained activated clay was measured for its physical and chemical properties to be as shown in Table (1).
  • Example 2 The dried acid activated clay was pulverized gently in a hammer mill & sieved to size 0.25mm to 2 mm diameter and rolled in a vibrosifter. The obtained activated clay was measured for its physical and chemical properties to be as shown in Table (1).
  • Example 2 Example 2:
  • Example 2 was carried out as per example 1 , where the acid-treated product was washed rapidly with water by circulating the washing water in a reactor at a speed of 333.4 lit/min and the total acidity was found to be 23.1 mg
  • Example 3 was carried out as per example 1 , where the acid-treated product was washed rapidly with water by circulating the washing water in a reactor at a speed of 1000 lit/min and the total acidity was found to be 24.5 mg
  • Example 4 was carried out as per example 1 , where the acid-treated product was washed rapidly with water by circulating the washing water in a reactor at a speed of 2000 lit/min and the total acidity was found to be 25.5 mg
  • Example 5 was earned out as per example 1, where the acid-treated product was washed rapidly with water by circulating the washing water in a reactor at a speed of 3000 lit/min and the total acidity was found to be 26.1 mg
  • Example 6 was carried out as per example 1 with a temperature of 83 degree C in the reactor with continuously circulating sulfuric acid and the total acidity was found to be 25.2 mg KOH/g.
  • Example 7 was carried out as per example 1 with a temperature of 85 degree C in the reactor with continuously circulating sulfuric acid and the total acidity was found to be 25.9 mg KOH/g.
  • Example 8 was carried out as per example 1 with a temperature of 89 degree C in the reactor with continuously circulating sulfuric acid and the total acidity was found to be 25.8 mg KOH/g.
  • Example 9 was carried out as per example 1 with a temperature of 91 degree C in the reactor with continuously circulating sulfuric acid and the total acidity was found to be 25.6 mg KOH/g.
  • Example 10 was carried out as per example 1 with a temperature of 93 degree C in the reactor with continuously circulating sulfuric acid and the total acidity was found to be 25.1 mg KOH/g. Tables:
  • Table 1 Chemical analysis of the smectite clay at different wash cycles, in accordance with the present invention, wherein,
  • Normal wash is 166.7 Lt/min as per example 1
  • Double wash is 333.4 Lt/min as per example 2
  • 3X- is 1000 Lt/min as per example 3
  • 6X is 2000 Lt/min as per example 4
  • Table 2 the surface area and total acidity of the smectite clay at different wash cycles in accordance with the present invention.
  • Fig. 1 of the accompanying drawings shows a graph of total acidity of the sample at different washing times, in accordance with the invention as shown in table 2. As the washing speed increases the washing time decreases and enhanced washing cycles gives a fixed total acidity.
  • Fig 2 of the accompanying drawings shows a graph bromine Index of the sample at different washing times, in accordance with the invention as shown in table 1.
  • a higher bromine index corresponds to a lower life of the catalyst hence BI is inversely proportional to the life of the catalyst.
  • Fig 3 of the accompanying drawings shows a graph of percentage of toluene generated of the sample at different washing times, in accordance with the invention. A higher toluene generated corresponds to a lower life of the catalyst hence toluene generation is inversely proportional to the life of the catalyst.
  • Fig 4 of the accompanying drawings shows a graph of capacity of the smectite clay catalyst formed in accordance with this invention at different wash cycles. The capacity increases with the increased speed of wash cycles.
  • Fig 5 of the accompanying drawings shows a graph of percentage of increase in life of the smectite clay catalyst formed in accordance with this invention at different wash cycles. Life of the catalyst increases with the increase in speed of the wash cycles, with a significant increase of 52%

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Silicates, Zeolites, And Molecular Sieves (AREA)
  • Catalysts (AREA)

Abstract

L'invention concerne un procédé d'activation d'argile smectite qui consiste: à sécher l'argile smectite; à nettoyer l'argile smectite séchée et à tester sa dureté; à séparer l'argile smectite inférieure à 2 Mohs dans des lots en vue d'un traitement ultérieur; à vérifier la valeur du bleu de méthylène de chaque lot de l'argile séparée et sélectionner les lots dont la valeur de bleu de méthylène est supérieure à 400mg/g en vue d'un traitement ultérieur; à ajuster l'humidité de l'argile à 30 - 40% par addition de 12 - 15% d'acide sulfurique; à extruder l'argile humidifiée jusqu'à une grosseur de grains de 12 à 15 mm; à traiter l'argile en grains dans un réacteur avec de l'acide sulfurique circulant en continu à une température de 80 - 95°C jusqu'à ce que l'acidité totale dépasse 22 mg KOH/g, et éliminer l'acide du réacteur; à laver l'argile traitée à l'acide à une vitesse comprise entre150 et 5000 lit/min avec de l'eau au cours de cycles accélérés pour éliminer les ions contenus dans l'argile hydrosoluble, tout en s'assurant que l'acidité totale de l'argile demeure supérieure à 22 mg KOH/g; à sécher l'argile lavée pour obtenir de l'argile traitée à l'acide présentant un degré d'humidité de 3 à 5%; et enfin, à transformer l'argile séchée en particules présentant une granulométrie principalement comprise entre 0,25 et 2 mm pour obtenir de l'argile smectite activée à l'acide.
PCT/IN2007/000527 2006-11-13 2007-11-07 Procédé amélioré d'acidification de l'argile WO2008059530A2 (fr)

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IN1876/MUM/2006 2006-11-13

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015085382A1 (fr) * 2013-12-10 2015-06-18 Labuto César Augusto Dumont Procédés impliquant l'addition d'acide sulfurique, produits obtenus et utilisation de ces produits
US10808076B2 (en) 2017-03-23 2020-10-20 The Dallas Group Of America, Inc. Purification of crude polyalkylene oxide polymers with acid functionalized silicas and metal silicates

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4832793A (en) * 1987-01-28 1989-05-23 American Colloid Company Process for extruding and acid treating clay for improved color development in carbonless copy paper
CN1236732A (zh) * 1999-04-21 1999-12-01 首都师范大学 一种湿法生产活性白土的制备方法
WO2004030811A1 (fr) * 2002-09-27 2004-04-15 Basf Aktiengesellschaft Catalyseur, procede de production de ce catalyseur et procede de polymerisation d'ethers cycliques sur ledit catalyseur

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4832793A (en) * 1987-01-28 1989-05-23 American Colloid Company Process for extruding and acid treating clay for improved color development in carbonless copy paper
CN1236732A (zh) * 1999-04-21 1999-12-01 首都师范大学 一种湿法生产活性白土的制备方法
WO2004030811A1 (fr) * 2002-09-27 2004-04-15 Basf Aktiengesellschaft Catalyseur, procede de production de ce catalyseur et procede de polymerisation d'ethers cycliques sur ledit catalyseur

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015085382A1 (fr) * 2013-12-10 2015-06-18 Labuto César Augusto Dumont Procédés impliquant l'addition d'acide sulfurique, produits obtenus et utilisation de ces produits
US20170008764A1 (en) * 2013-12-10 2017-01-12 César Augusto Dumont Labuto Processes involving sulphuric acid addition, products obtained and use of said products
US10829375B2 (en) * 2013-12-10 2020-11-10 César Augusto Dumont Labuto Process for treating material with sulfuric acid and materials obtained thereby
US10808076B2 (en) 2017-03-23 2020-10-20 The Dallas Group Of America, Inc. Purification of crude polyalkylene oxide polymers with acid functionalized silicas and metal silicates

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