Activated carbon specific surface area analyzer - Database & Sql Blog Articles

Activated carbon, also known as a carbon molecular sieve, is a black porous solid made from carbon. It has an extremely high surface area, typically ranging between 500 and 1700 m²/g, making it one of the most effective adsorbents in industrial applications. Its unique pore structure allows it to trap and hold various pollutants, making it widely used in air and water purification systems.

One of the key features of activated carbon is its exceptional adsorption capacity. The more developed the pores and the larger the surface area, the greater the ability to absorb impurities. This makes it highly effective for removing toxins, odors, and other harmful substances from gases and liquids.

The adsorption characteristics of activated carbon are closely tied to its surface properties. The BET (Brunauer–Emmett–Teller) method is the standard technique used to measure the specific surface area of activated carbon, ensuring accurate and reliable results. In China, the GB/T 19587-2004 standard outlines this process, which is also widely adopted internationally. Instruments like the JW-DA specific surface area tester provide precise and automated BET measurements, offering high accuracy and user-friendly operation. This equipment has been exported globally and is known for its stability and advanced software design.

Here is a table showing the adsorption capacity of activated carbon for different gases (in ml/cm³):

Hâ‚‚: 4.5 | Oâ‚‚: 35 | Nâ‚‚: 11 | Clâ‚‚: 494 | COâ‚‚: 97

In addition to adsorption, activated carbon also exhibits catalytic properties. During the adsorption process, it can act as a catalyst, facilitating chemical reactions. For example, it can catalyze the oxidation of sulfur dioxide into sulfur trioxide or help in the formation of phosgene from chlorine and carbon monoxide.

Its catalytic activity is enhanced when it acts as a support for metal salts, such as palladium or copper. These complexes significantly improve reaction efficiency, speed, and selectivity. Activated carbon is often used as a carrier for precious metal catalysts in organic chemistry, such as platinum and palladium, in reactions like hydrogenation and dehydrocyclization.

When it comes to mechanical properties, several factors determine the performance of activated carbon:

• Particle size: Measured using a standard sieve system to determine distribution.
• Bulk density: Refers to the weight per unit volume, including both pore and interparticle spaces.
• Particle density: Measures the weight per unit volume without considering intergranular voids.
• Strength: Indicates how resistant the carbon is to crushing.
• Abrasion resistance: Reflects its ability to withstand wear and friction.

These properties directly impact its practical use. For instance, density affects container size, particle size influences filtration efficiency, and strength determines the lifespan of the carbon during repeated use and regeneration.

Chemically, activated carbon contains not only carbon but also functional groups like carbonyls, carboxyls, phenols, lactones, and ethers. These groups contribute to both physical and chemical adsorption. Additionally, during activation, minerals from the raw material form ash, mainly composed of alkali metal and alkaline earth metal salts, which can be removed through washing or acid treatment.

Overall, activated carbon is a versatile material with a wide range of applications due to its unique combination of physical, chemical, and mechanical properties.