RU2177907C2 - Method of preparing activated carbon - Google Patents

Abstract

FIELD: food, chemical industries and municipal service. SUBSTANCE: method comprises carbonization of charcoal by heating it to 830 C and activation by supplying steam, supply of steam for activation purposes is carried out at temperature of 150 C and pressure of 4-6 atm and activated carbon temperature is reduced to 750 C and carbonization and activation are then repeated, and greater blue methylene capacity is attained. EFFECT: more efficient preparation method. 1 tbl

Description

 The invention relates to the production of activated carbon from wood and can be used in food, chemical industry and utilities.

A known method of producing activated carbon from a carbon-containing material, in which carbonization is carried out by heating to 550-650 ^o C, and activated by water vapor when reaching a temperature of 900-950 ^o C (see Russian patent N 2023663, 01 01 31/08, from 10.21.93, publ. 11.30.94).

 The disadvantage of this method is the weak adsorption activity of coal according to "methylene blue".

A known method of producing activated carbon, including the carbonization of charcoal by heating it to 830 ^o C and activation by supplying water vapor (see Russian patent N 2114057, 01 01/31/08 from 08/07/97, publ. 06/27/98 - prototype) . The disadvantage of this method is the complexity of its implementation and the low adsorption activity of coal according to "methylene blue".

The objective of the invention is to simplify the method of production of activated carbon and increase its adsorption activity according to "methylene blue". The problem is solved by the method of producing activated carbon, including carbonization of charcoal by heating it to 830 ^o C and activation by supplying water vapor, according to the invention, the supply of water vapor for activation is carried out at a temperature of 150 ^o C and a pressure of 4-6 ati to lowering the temperature of coal to 750 ^o C, after which the process of carbonization and activation is repeated.

 A comparative analysis of the proposed solution with the prototype allows you to highlight the features that distinguish the proposed method from the prototype, which meets the criterion of "novelty."

 Analysis of technical solutions did not reveal among them solutions that match the distinguishing features of the proposed method, which meets the criterion of "inventive step".

 The method is as follows.

Partially carbonized birch charcoal is taken, it is loaded into the hopper, heated to a temperature of 830 ^° C, without air access, then an opening is opened for the exit of gases and ignited, steam is supplied with a temperature of 150 ^° C and a pressure of 4-6 bar, steam is activated up to reaching a temperature of coal 750 ^o C. After this, the activation is stopped. If necessary, the carbonization and activation process is repeated 2 times or more.

Temperature and pressure are selected experimentally. When the pressure drops below 4 atm and the vapor temperature is below 140 ^o C, the activation process slows down sharply, resulting in activated carbon with low activity "according to methylene blue". When the pressure rises above 5 ati and temperature above 160 ^o C, energy costs sharply increase with a slight increase in the activation process. The temperature of coal 830 ^o With selected experimentally, since with increasing temperature there is a sharp increase in the "burning" of coal, with a decrease in temperature below 830 ^o With the carbonization process does not end, and therefore the yield of activated carbon with high activity decreases sharply.

Example 1. Take 22.5 kg of partially carbonized birch coal with a fraction of 3-6 mm, load into the hopper, seal it, heat it to a temperature of 830 ^o C, open the gas outlet, ignite the gas, activate it with steam with its temperature of 150 ^o C and pressure of 4-6 ati from the steam generator EK-25. Activation is carried out until the coal temperature reaches 750 ^o C. The process of carbonization and activation is repeated 3 times. Then the hopper is sealed and left in the open air until it cools completely. After cooling, the coal is removed and weighed, and also analyzed for adsorption activity. 15.5 kg of activated carbon with adsorption activity of "methylene blue" of 225 mg / g are obtained.

 Example 2. Take 15.5 kg of activated carbon, carry out the same operations as in example 1.

 Obtain 11 kg of activated carbon with adsorption activity on the "methylene blue" 287 mg / g

Example 3 (prototype). Take 20 kg of partially carbonized birch coal with a fraction of 3-6 mm, placed in a hopper and carbonized in an oven at a rate of rise of temperature of 40-60 deg / min to a temperature of 800-850 ^o With no access to air. Then steam activation is carried out at a ratio of raw coal and steam equal to 1: (5-8), then activated carbon is discharged and cooled to ambient temperature.

 The resulting activated carbon has a methylene blue adsorption capacity of 180 mg / g.

 The data obtained are summarized in a table.

 Thus, the proposed method allows to obtain activated carbon with an adsorption capacity of "methylene blue", superior to the adsorption capacity of coal obtained by other methods.

Claims (1)

A method of producing activated carbon, including carbonization of charcoal by heating it to 830 ^{° C.} and activation by supplying water vapor, characterized in that the steam is supplied for activation at a temperature of 150 ^{° C.} and a pressure of 4-6 atm until the temperature of the coal decreases to 750 ^o C, after which the process of carbonization and activation is repeated.

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