Separation of Carbon from Liquid or Gas

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C

Carbon

Carbon forms many uncharged compounds in which removal relies on weak Van Der Waal force of adsorption and carbon also forms many other charged compounds in which removal depends on the type of application.
 

Please select the type of carbon compound requiring removal to refine the recommendation.

Carbonic and Organic Acids

Carbonic acids and organic acids and their salts of the general form R COO- are anions so they can be captured with anion exchange resins. Cyanide is another anionic carbon compound that can act like a weak acid. When these compounds are present as acids, they can be captured from both liquid and air streams with an acid absorber like AMBERLYST™ A21 Resin.

When the stream is not acidic, a strong base resin like DOWEX™ 21K XLT Resin will be required.

For streams that have a high content of organic material and are prone to surface fouling, DOWEX MARATHON™ MSA Strong Base Anion Exchange Resin is recommended.

VOCs (Volatile Organic Compounds)

  • Volatile Organic Compounds—VOCs—are uncharged carbon-containing compounds that lack an “ionic handle” so they must be removed by adsorption. DOWEX OPTIPORE™ Polymeric Adsorbents offer an alternative to activated carbon for the removal of a wide variety of organic compounds.
  • Please see the special page in the Markets section for product recommendations:
  • Chemical & Petrochemical → Selective Contaminant Removal → VOCs

BTEX

  • Benzene, toluene, ethylbenzene, and xylenes—collectively known as “BTEX”—are some of the volatile organic compounds (VOCs) found in petroleum derivatives. These compounds, like other VOCs, are uncharged carbon-containing compounds that lack an “ionic handle” so they must be removed by adsorption. DOWEX OPTIPORE™ Polymeric Adsorbents offer an alternative to activated carbon for the removal of a wide variety of organic compounds.
  • Please see the special page in the Markets section for product recommendations, depending on your application:
  • Oil Field Water → Produced Water → BTEX Removal
  • Waste Water & Reuse → Selective Contaminant Removal → VOCs/BTEX

NOMs (Natural Organic Matter)/DBPs (Disinfection By-Products)

Natural Organic Matter (NOM) is found in many surface water sources and is the by-product of decay of organic materials such as plant matter. In its natural state, NOM poses no specific health risk, although it does give water a yellow tint that can be an aesthetic issue. However, when hypochlorite and chlor-amines are used as disinfecting agents, these oxidants can react with NOM to generate regulated compounds called Disinfection By-Products (DBPs). Removing NOM reduces DBPs.

Please see the special page in the Markets section for product recommendations:

Decolorization

Decolorization is a crucial step in a variety of applications within the food and beverage industry. It is used: 1) in the final polishing of starch-based sweeteners, 2) to facilitate efficient crystallization of white sugar with minimal sugar loss to molasses as well as meeting increasingly stringent quality specifications for colorless sugar syrups, and 3) as part of the process to make a neutral base for converting fruit juice to a designed beverage or to create juice for canning or blending as a supplemental natural sugar source.

Please see the special page in the Markets section for product recommendations, depending on your application:

Aromatic & Phenolic Compounds from Wastewater

Many of the materials produced by the phenol industry are toxic and cannot be discharged without treatment. Current treatment processes usually involve biological degradation, chemical oxidation or adsorption on activated carbon. Sensitive to operating conditions, these processes can perform inconsistently and destroy the product. Because organic concentrations in waste water tend to be high (1–5%), especially for phenol, recovery of that organic waste can result in substantial cost savings. Polymeric adsorbents are insoluble engineered polymers capable of removing synthetic organics from water.

Please see the special page in the Markets section for product recommendations:

Organic Scavenging

Some water sources contain an excessive amount of Natural Organic Matter (NOM) which can foul anion exchange resins. While this fouling can generally be cleaned, it can lead to reduced system availability and shorter resin life. The use of an organic scavenger in front of any demineralization equipment, including reverse osmosis, is an inexpensive solution to protecting membranes and resin from organic fouling.
Carbon is the most diverse element and exists in a wide variety of chemical compounds. It is not possible to discuss all the different compounds of carbon and how they can all be separated, so general guidelines are given for further investigation.