ES2301381B1 - ACTIVE CARBON OF VEGETABLE ORIGIN AND PROCEDURE OF OBTAINING. - Google Patents

Abstract

Active carbon of plant origin and procedure of obtaining.

The invention relates to an active carbon consisting of whole olive bones and the procedure for their  obtaining, material that, by keeping the shape of the bone intact and its resistance, and for its properties physicochemical, is useful for various Domestic applications such as: stuffing of medicinal pillows, negative ion generator, field attenuation Electromagnetic, fruit and vegetable aging retarder fresh and / or elimination of strange flavors and odors in the Water.

Description

Active carbon of plant origin and procedure of obtaining.

Field of the Invention

The invention relates to an active carbon consisting of whole olive bones and the procedure for its obtaining, material that, for its geometric properties and physicochemical, is useful for various Domestic applications such as: stuffing of medicinal pillows, negative ion generator, field attenuation electromagnetic, fruit aging retarder and fresh vegetables and / or elimination of strange flavors and odors in the Water.

Background of the invention

The active carbon in its broadest sense comprises a large number of amorphous carbonaceous materials that exhibit a high degree of porosity and a high internal surface. In general they are obtained by combustion, partial combustion or pyrolysis of various carbonaceous materials of both vegetable and mineral origin. Since ancient times, the use of various carbonaceous materials for human use applications is common. In 1500 BC the Egyptians used charred wood as a medicine and the ancient Hindus used it for the filtration of drinking water (1). This ability of coal to adsorb pollutants is due to its microcrystalline and relatively disordered structure, called a turbostratic structure (2,3), as opposed to the more orderly and inert gratifying structure (3). From the initial carbonized, which is already active, porosity can be further developed by subjecting the material to the action of oxidizing agents such as carbon dioxide or water vapor, eliminating the most disorganized carbon from pyrolysis and leaving a clean microporous structure (1). In addition to the porous microcrystalline structure, the activity of the carbon is due to missing electrons in certain positions of the basal planes and that make it very reactive (1). These unsaturated valences tend to be saturated with oxygen mainly (4) and hydrogen, giving carbon good adsorbent properties for a wide variety of compounds (5). Consequently, coal, due to its adsorbent and catalytic properties, is an ideal material in processes of purification of both liquids and gases. Activated carbon, which is currently used in the food, chemical, pharmaceutical and environmental industries (6), however, is not so widely used domestically, at least in Western countries. However, the domestic use of charcoal, mainly holm oak and bamboo, is common practice in Eastern countries such as Japan (7). In this country, these coals are sold in various formats: " Ubamegashi " ( Quercus phillyaeorides ) oak branches , which receives the trade name of Bincho (7) or whole carbonized bamboo plates (8), the same materials in finer granules in bags or introduced in adsorbent containers for the elimination of odors in cupboards or in closed places or to delay the aging of fresh fruits and vegetables (7), these same branch materials introduced in compartmentalized tatamis for use as moisture and odor adsorbents body (7), the previous format but introduced in special containers for use in bath water, the micronized material and incorporated into soaps or gel suspensions as a cosmetic product (7,9) the same granulated carbons introduced in special containers for the absorption of electromagnetic radiation emitted by household appliances, the same format but introduced in pillows or cushions or the same chopped coals for use in ovens and yakitoris (barbecues) (7). In summary, the applications given to these materials at home can be classified into the following groups with the following applications:

Improvement of environmental conditions

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Odor Elimination environmental

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Moisture removal environmental

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Radiation elimination environmental

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Negative ion generation

Food and water improvement

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Increase in water purity

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Vegetable preservation fresh

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Source of heat in ovens and barbecues

Medicinal and cosmetic uses

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Bath water additive

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Soaps and gels component

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Stuffed with pillows and cushions

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Broad spectrum antidote

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Bibliography

1. Bansal , RC and Goyal , M. ( 2005 ) Activated Carbon Adsorption . CRC press, 2005.

2. Biscoe , J. and Warren , GE, J. Appl. Phys ., 13, 364, 1942 .

3. Bokros JC Chemistry and Physics of Carbon , PL Walker, Jr., ed., Vol. 5, Marc Dekker, 1969 .

4. Kipling JJ, Quart. Rev. , 10, 1, 1956 .

5. Rideal , EK and Wright , MW, J. Am. Chem. Soc ., 1347, 1925 .

6. Roskill . The Economics of Activated Carbon , Roskill Information Sevices Ltd. London 1998 .

7. www.murayoshi.com

8. www.linanwindow.com

9. www.tanagokoro.com

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Detailed description of the invention

The present invention provides a material to carbon base of variable activity produced from bone of whole olive that retains the exact shape of the material original and its mechanical strength and manufacturing method that It comprises the following stages:

a) Washing of the raw material by means of a jet of pressurized water between 15 and 200 bars of pressure and at a temperature between 15ºC and 95ºC.

b) Drying the impregnated material or without impregnate at a temperature between 30ºC and 90ºC for a while variable between 10 minutes and 3 hours.

c) Preheating the material to a temperature between 100ºC and 400ºC for a variable time between 10 minutes and 3 hours

d) Pyrolysis of the material in an atmosphere of Nitrogen or carbon dioxide or any gas in the group of noble gases, or any mixture of these gases, at a temperature between 280 ° C and 1000 ° C or preferably between 500 ° C and 600 ° C and for a time between 15 minutes and 3 hours and at a gas flow rate between 0.1 and 10 volumes of raw material initial per minute.

e) Cooling of the previous material in it pyrolysis atmosphere for a variable time between 1 hour and 24 hours.

The process that follows these stages can be operate both continuously and in batches.

As a result of the previous process you get a carbon material that retains exactly the shape of the original material and maintains its mechanical strength, with a apparent density between 350 and 450 g / l, with a higher ASTM hardness 95%, with a specific surface area (BET) between 1 and 750 m 2 / g, with a microporosity (DR) between 2.14x10 -4 and 0.20 cm3 / g, capable of adsorbing various volatile compounds such as indole, putrescine, ethylene, trichloromethane and monochloramine between others, capable of generating negative ions and totally free of powder, becoming an ideal material for applications domestic as network water filtration, odor adsorbent, conservation of fresh vegetables, negative ion generator and pillow stuffing

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Example 1

Starting from 1 kg clean material (fig 1), it is dried at room temperature for 1 hour and introduced into a pyrolysis oven with a nitrogen atmosphere. Be heats up to 400º and stays 1 hour at that temperature in Nitrogen current. The oven is then brought to 500 ° C and it stays 40 minutes at that temperature in current of Nitrogen. Finally the oven is turned off and the material for 24 hours in nitrogen atmosphere.

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As a result, a material is completely obtained carbonized that retains the shape of the starting material, with a macropore structure where pores are seen from 0.3 µm up to 20 µm revealed by scanning electron microscopy (fig 2) and with the following technical characteristics:

- Bulk density of 410 g / l

- BET specific surface area of 1.2 m2 / g

- Micropore volume of 2.14 10-4 cm3 / g

- 98% ASTM D 3802 hardness index

- pH of 9.34

- Dimensions: 4 x 8 mm ovoids.

Likewise, the capacity of the material is checked obtained in this example to absorb odors, moisture, trihalomethanes and water chloramines, as well as their ability to generate negative ions and preserve fruits and vegetables. These essays They are performed as follows:

one.

Adsorption of odors

They were chosen four chemicals to study the capacity of the material as an odor eliminator The selected products were indole, piperidine, putrescine and ammonia. Indole is solid to room temperature and produces an intense smell of feces. Piperidine It is a clear liquid with the smell of pepper. Putrescina is responsible the smell of urine and bad breath and ammonia is the cause of the smell of cat urine. The measure of odor intensity is performed using a panel of 8 experts who rated the 0-4 odor intensity (no odor = 0; same intensity than the control = 4). The material in this example reduced the intensity of the smell of indole in 37.5%, putrescine in a 57.5%, to piperidine in 52.5% and to ammonia in 77.5% (fig 3).

2.

Adsorption of trihalomethanes and chloramines

The trihalomethanes and chloramines are families of compounds chlorinated that occur in the water as a result of the reaction of chlorine dosed in sewage treatment plants or other halogens (fluorine or bromine as more frequent) and methane and ammonia respectively. As compounds for the test, trichloromethane and Monochloramine The test was done adsorption was done both in static as in dynamic. In the first case they faced different concentrations of coal at the same concentration of pollutant and the reaction is allowed to proceed for a long time enough for balance to be reached and then the residual concentration of the contaminant in the water is measured and Calculate the% of pollutant removed by coal. The latter value is plotted based on the weight of coal used in the trial. The results appear in Figure 4 for trichloromethane and monochloramine. In the case of the trial dynamic you put a certain amount of material in a fill column that is passed through for a while determined and at a given flow rate, a solution of a known concentration of the contaminant. Every certain interval of time the effluent solution is sampled and the concentration is measured of the contaminant The results are represented as concentration of contaminant in the effluent as a function of time. The results of this test appear in figure 5 for the trichloromethane and monochloramine and the ability of the material to remove these pollutants from water.

3.

Negative ion generation

Ions negatives are generated in the air by reactions that can reach be very complex involving radical chain reactions free. These negative environmental ions supposedly have a positive influence on human health. In the case of coal active, these ions would be generated by electron uptake missing from the basal plates by certain molecules Present in the air. To perform this test they were introduced in a closed glass vessel the ion measurement probe negatives and a certain amount of coal from the example, the air inside the chamber being recirculated by means of a device included in the measuring probe itself. Every true time interval the concentration of negative ions was measured in the air in the chamber The experiment was performed both in the presence as in the absence of coal. The results appear in figure 6 as a concentration of negative ions as a function of time. The results show the ability of the material to generate ions negative

Four.

Moisture absorption

Due to the high specific surface area and the presence of molecules of oxygen covalently bonded to the material's carbon, carbon The example is a good moisture sensor. In this essay you introduced 5 grams of coal in a humidity controlled chamber and was subjected to various humidity cycles measuring the capacity Reversible moisture absorption. The material was shown as a good moisture sensor compared to other materials such as sepiolite or bincho as shown in the figure 7.

8.

Vegetable preservation

It is known the ability of active carbons to adsorb ethylene, hormone vegetable produced during the dehiscence of the fruit and responsible for its aging Through this process the Phanerógamas plants (plants with fruit) release the new seeds of the fruit thus allowing its reproduction. This test was performed on tomatoes for which four tomatoes were placed in boxes of 24x16x10 cm (3.84 l). Four groups were made: control, 5 g, 10 g and 20 g of charred olive bone. The temperature was maintained at 21 ° C and 60% humidity. Tomatoes were checked every three days for of symptoms of maturation. On day 34 the tomatoes were cut in two pieces.

The outer appearance of tomatoes was, in all the good case, but inside it was appreciated that tomatoes preserved with charred olive bone, they did not present growth of radicles and retained the moisture and smell of tomato cool. In the case of control, the interior of the tomato presented multitude of radicles, dry appearance and without the characteristic smell of tomato

Claims (7)

1. Method of manufacturing a carbon material characterized in that it starts from whole olive bone and comprises the following steps:

to)

Raw material wash

b)

Material drying

C)

Material preheating

d)

Pyrolysis-activation of the material

and)

Cooling of the previous material in the same pyrolysis atmosphere for a variable time between 1 hour and 24 hours

2. Method according to claim 1 characterized in that the preheating is carried out at a temperature between 100 ° C and 400 ° C for a variable time between 10 minutes and 3 hours. 3. Method according to claim 1, characterized in that the pyrolysis is carried out under an atmosphere of Nitrogen or carbon dioxide or of any gas of the group of noble gases, or any mixture of these gases. 4. Method according to claim 1 and 3 characterized in that the pyrolysis is carried out at a temperature between 280 ° C and 1000 ° C or preferably between 500 ° C and 600 ° C and for a time between 15 minutes and 3 hours. 5. Method according to claim 1 and 3 characterized in that the gas flow rate is maintained between 0.1 and 10 volumes of initial raw material per minute. Method according to claims 1 to 5, characterized in that the process is carried out both continuously and in batches. 7. Carbon material with varying degree of activation characterized by being a whole carbonized olive bone that preserves exactly the shape and mechanical properties of the raw material and that meets the following specifications:

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Bulk density between 350 and 450 g / l

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Hardness ASTM greater than 95%

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Specific surface area (BET) between 1 and 750 m2 / g

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Microporosity (DR) between 2.14x10-4 and 0.20 cm3 / g