Activated carbon adsorption principle

Activated carbon is a kind of very fine carbon particles with a large surface area, and there are even smaller pores in the carbon particles-capillaries. This kind of capillary has a strong adsorption capacity, and due to the large surface area of the carbon particles, it can fully contact with the gas (impurity). When these gases (impurities) meet the capillary, they are adsorbed and play a role in purification. The research on the surface area of activated carbon is very important. The specific surface area of activated carbon can only be tested by the BET method. The results are real and reliable. At present, there are many instruments in China that can only be tested by direct comparison method, and now they are also eliminated in China. At present, the specific surface area test at home and abroad adopts the multi-point BET method uniformly. The specific surface area measurement standards formulated at home and abroad are all based on the BET test method. Please refer to my country's national standard (GB/T 19587-2004) - gas adsorption BET principle A method for determining the specific surface area of ​​a solid substance. The specific surface area detection is actually a time-consuming task. Due to the difference in the adsorption capacity of the samples, the test of some samples may take a whole day. If the test process is not fully automated, the test personnel cannot leave at all times and must High concentration, observing the instrument panel, manipulating the knob, a little carelessness will lead to the failure of the test process, which will waste a lot of precious time of the testers. F-Sorb 2400 specific surface area tester is an instrument that can truly realize the detection function of BET method (also with direct comparison method). More importantly, F-Sorb 2400 specific surface area tester is the only fully automated and intelligent specific surface area testing equipment in China so far. , the test results are highly consistent with international standards, and the stability is also very good, while reducing human errors and improving the accuracy of test results. Adsorption capacity of activated carbon for various gases (unit: ml/cm3): H2, O2, N2, Cl2, CO2 4.5, 35, 11, 494, 97

Activated carbon catalytic

Activated carbon is accompanied by catalytic reactions in many adsorption processes, showing the activity of catalysts. For example, activated carbon adsorbs sulfur dioxide and converts it into sulfur trioxide through catalytic oxidation. Due to the existence of specific oxygen-containing compounds or complexes on the surface of activated carbon, it has catalytic activity for various reactions, such as making chlorine and carbon monoxide generate phosgene. Since a complex is formed between the activated carbon and the support, this complex catalyst greatly increases the catalytic activity. For example, the activated carbon loaded with palladium salt can catalyze the oxidation of olefins even without the presence of a copper salt catalyst. And fast, high selectivity. Because activated carbon has a well-developed pore structure, a huge internal surface area and good heat resistance, acid resistance, and alkali resistance, it can be used as a catalyst carrier. For example, activated carbon is an excellent carrier for platinum and palladium catalysts in reactions such as hydrogenation, dehydrocyclization, and isomerization in organic chemistry.

Activated carbon mechanical properties

(1) Particle size: Use a set of standard sieve sieving methods to find the weight of activated carbon remaining and passing through each sieve, indicating the particle size distribution.

(2) Static density or bulk density: the weight of activated carbon per unit volume of dietary pore volume and intergranular void volume. the

(3) Bulk density and particle density: the weight per unit volume of activated carbon that eats the pore volume but not the inter-particle void volume. the (4) Strength: that is, the crush resistance of activated carbon.

(5) Abrasion resistance: that is, the performance of wear resistance or anti-friction. These mechanical properties directly affect the application of activated carbon, for example: density affects the size of the container; the thickness of powdered carbon affects filtration; the particle size distribution of granular carbon affects fluid resistance and pressure drop; fragmentation affects the service life of activated carbon and the regeneration of waste carbon.