Activated Carbon Decolorizing Properties
CARBOCHEM produces a full line of activated carbon (pellets, granular, & powder) based on coal, wood and coconut shells with special emphasis on water treatment, food & beverage, chemical processing and pollution control. CARBOCHEM® activated carbon has been certified for ASNI/NSF Standard 61 and ISO 9002 and satisfies the requirements of the Food Chemical Codex.
Decolorizing applications involve removal of large molecular compounds which require activated carbon with a well developed macropore structure. The information provided here applies to sugar refining but the same concepts and principles apply to other decolorizing applications.
Adsorption Process of Activated Carbon
Activated Carbon is non-polar which results in an affinity for non-polar compounds such as organics. These compounds are bound to the surface of the activated carbon by the adsorption process, which utilizes Van der Waal forces. Since adsorption is a surface phenomenon, the adsorption capacity is directly related to the pore structure and surface area of an Activated Carbon and saturation is only achieved under equilibrium conditions. The equilibrium point is determined by parameters such as temperature, pH, concentration and contact time. Particle size only affects the rate of adsorption and has negligible impact on Total surface area, which is determined by the degree of activation and pore structure. It is important to remember that adsorption is not a selective process but will depend on the specific adsorption affinity of each compound which is related to parameters such as molecular size and solubility.
Properties of Activated Carbon
There is no universal activated carbon which is ideal for every application so it is important to match the properties of the activated carbon with the performance requirements of the process. The primary parameters used in the industry are given as follows with the corresponding indicators:
Apparent Density - volume activity
Iodine Number - surface area and micropore content
Molasses Number/Caramel dp - macropore content (pore > 500 Å)
These parameters give an indication of the relative adsorption capacities of different activated carbons and their corresponding service lives for a specific process (even though an activated carbon may have a high surface area it also needs to have the right pore structure to be effective). Activated Carbon with high macropore content will provide the best decolorizing performance.
Decolorizing Performance of Activated Carbon Key Parameters:
Decolorizing Performance - pore volume
Filterability - particle size
Color Stability - removal of precursors of degradation by-products
Activated Carbon Evaluation Process
It is important to establish a well defined Test Protocol so that the operating parameters are the same for each activated carbon being evaluated.
Fixed Parameters:
- Quality of feedstock
- Temperature
- Contact time
- Activated carbon dose rate
- Particle size of activated carbon
- pH of color measurement
Activated Carbon Selection and Optimization
- Granular activated carbon vs. powdered activated carbon
- Dose rate
- Contact time
- Particle size of activated carbon
- Temperature vs. viscosity
Carbochem Inc. has been supplying activated carbon to the sugar industry for more than 10 years and has developed the following specialized grades to optimize decolorizing performance:
Carbochem® DC-40: granular activated carbon
Carbochem® CA-10: powdered activated carbon
We welcome any inquiries and the opportunity to discuss your activated carbon requirements.
Ion Exchange Resins
CARBOCHEM offers a full line of Ion Exchange Resins (cation, anion, mixed bed & selectives) with applicability in household & industrial softening, boiler feedwater, food & beverage, electronics, and wastewater treatment. IonPlus TM ion exchange resins are produced under ISO 9002 certification.
Activated Carbon Manufacturer & Chemical Supplier: Industrial Chemicals
- Cerium Products: Carbonate, Oxide
- Chrome Oxide
- Cobalt Products: Carbonate, Oxide, Sulfate
- Copper Oxide
- Molybdenum Products: Ammonium Heptamolybdate, Molybdenum Trioxide, Ammonium Dimolybdate
- Neodymium Oxide
- Nickel Products: Carbonate, Oxide, Sulfate
- Niobium Oxide
- Potassium Nitrate
- Tin Sulfate
- Tungsten Products: Ammonium Metatungstate, Sodium Tungstate
- Titanium Dioxide: Anatase
- Zirconium Products: Carbonate, Oxychloride, Sulfate
