Because of these pores, especially the micropores provide a large surface area.
The pore volume of activated carbon micropores is generally only 0.25-0.9mL/g, the number of pores is about 1020 lg, and the surface area of all micropores is about 500-1500m2/g, which is usually measured by the BET method, and it is also said to be as high as 3500-5000 m2/g.
Activated carbon almost more than 95% of the surface area is in the micropore, so in addition to some macromolecules can not enter, micropore is an important factor to determine the adsorption performance of activated carbon.
The pore volume of mesopores is generally about 0.02-1.0 MLLg, and the surface area can be up to several hundred square meters, generally only about 5% of the total activated carbon silkworm species.
Its function can adsorb steam, and can provide a channel for adsorbent to enter the micropore, and can directly adsorb larger molecules.
The pore volume of the macropore is generally about 0.2-0.5mL /g, and the surface area is only about 0.5-2m2 /g. Its role is to make the adsorbate molecules quickly penetrate into the smaller pores inside the activated carbon.
: as a catalytic carrier, the catalyst is often a small amount of precipitation in the micropore, mostly precipitation in the macropore and mesopore.
The surface area of the activated carbon should include the inner surface area and the outer surface area. In fact, the adsorption properties mainly come to the inner surface area of the white Li large, so it can not be mistaken for: the activated carbon grinding and grinding will significantly improve the surface area to improve the adsorption force.activated charcoal manufacturers
Many adsorbations are recursive physical adsorption, that is, the adsorbed matter is a fluid, which is adsorbed by activated carbon at a certain temperature and pressure. At high temperature and low pressure, the adsorbed matter desorbs out, and the inner surface of activated carbon returns to its original state.activated carbon is a kind of very small granular has a large surface area, and more tiny holes in the granular - capillary. The capillary has very strong adsorption capacity, due to the granular surface area is large, so a good contact with with gas (impurities). When these gases (impurities) encounter capillary by adsorption, purification effect. Activated carbon surface area of the study is very important, only the BET specific surface area detecting data of active carbon method detected result is reliable, domestic at present there are many instruments can only make direct comparison method of detection
Preparation method of granular activated carbon is mainly physical activation method [12 and chemical activation method [3.821]. Physical activation method is to dry, carbonized materials will be first, and then carbonized material crushing, then add to the crushing carbonized material, the binder and its mixing, forming and drying grain charcoal, then the granular activated carbon under a certain temperature, the final results of dry granular activated carbon products. The method commonly used activation main gas water vapor and carbon dioxide [20] [l ⒂ 5]. The physical activation method is characterized by high activation temperature (generally at about 900 ℃), the equipment investment is large, step trival,
But the pollution to the environment is relatively small.The purification efficiency of liquid absorption method is 60%~ 80%, which is suitable for treating low concentration and large volume of organic waste gas, but there are secondary pollution.
The purification rate of catalytic combustion method is 95%, which is suitable for the treatment of high concentration and small air volume organic waste gas. The disadvantage is that it has strict requirements on the treatment object and requires high gas temperature. In order to improve the exhaust gas temperature, it needs to consume a lot of fuel, so the operation cost is very high.activated carbon for gold extraction