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Purification & Separation

Development of lower cost methods for chemical purification and separation is of particular interest to the chemical and petrochemical industries. A particular challenge is in the separation of organic compounds with very similar physical properties such as boiling point. Current industrial practices focus on separation by crystallization, adsorption through porous solids, or fractional distillation.


ONC compounds exhibit a strong extraction capability that can be tuned to absorb certain organic compounds with high selectivity. The shape and topology of the ONC crystal pores enable it to preferentially separate very similar organic compounds that only differ in their molecular shape and orientation. This molecular-level shape recognition by ONC porous crystals offers a more selective approach to separating out different organic compounds compared to the current energy-intensive separation technologies that rely on separation through differences in macroscopic physical properties.



Advantages of using ONC separation technology:



  • ONC adsorption filters offer an energy-efficient separation process for petrochemicals and other chemical raw materials. It shows a substantial improvement in selectivity for separating industrially important feedstocks.



  • ONC materials are scalable to build industrial-sized filters for high-throughput separation and purification requirements.



  • Standard methods of separating hydrocarbons involve energy-intensive cryogenic distillations. ONC filters have been developed to do full separation, at ambient temperatures and pressures, of benzene, ethylbenzene, toluene, and the xylene isomers (BTEX compounds) that are commonly found in petroleum products.



  • ONC filtration systems are tuned to separate molecules through the nano-cubes' selective absorption of different isomers, chirality, shape, and functional groups.



  • A filtration technology to separate and purify important industrial chemicals, including petrochemicals, flavoring and fragrance molecules, and pharmaceutical chemicals.

ONC materials are green, renewable, biodegradable, and safe to use in manufacturing.

Highly Selective Separation Fiber

  • Manufacture high-selectivity filtration material using nano-cubic crystals


  • Petrochemical separation is an energy-intensive process, but nano-engineered separation technology offers low-cost, low energy solutions


  • Novel developement of filters have been shown to successfully isolate the volatile BTEX compounds


  • Used as an adsorbent material for chromatographic separation, ONC crystals can be applied for purifying flavoring and fragrance molecules, pharmaceutical compounds, and other speciality chemicals

Fragrance & Flavor Molecules

  • Important precursors for perfumery



  • Pinenes are bicyclic alkenes that consist of 2 configurational isomers with enantiomers (4 isomers total)



  • All isomers are naturally occurring (pine resin)



  • All 4 isomers can be separated and purified with ONC filter materials



  • For both enantiomers, the isomer with an exocyclic double bond is retained longer in the ONC filter than the isomer with an endocyclic double bond

BTEX Separation

  • BTEX mixture can be separated into pure components


  • All separations achieved at ambient temperature and pressure


  • ONC crystals, a renewable material, can facilitate the separation of petrochemical compounds

Limonene Separation

  • Limonene enantiomers are successfully separated with ONC filters



  • Limonene occurs naturally in lemon rind as the (R)-enantiomer



  • R-enantiomer has a citrus odor



  • S-enantiomer has a piney odor

Purification of Chiral Molecules

  • ONC materials can produce HPLC columns capable of separating chiral compounds


  • Can be utilized in separation and purification of pharmaceutical chemicals

Styrene Purification

  • Styrene is produced by catalytic dehydrogenation of ethylbenzene


  • Separation by distillation of very similar boiling points


  • ONC filters demonstrate clean separation of styrene from ethylbenzene


  • ONC filters also demonstrate clean separation of alpha-methylstyrene from cumene

Haloaromatic Compounds

Left Plot:

  • Strong binding of haloaromatic compounds to ONC framework


  • Retention order F > Cl > Br > H > I


Right Plot:

  • Bromine and methyl groups have very similar steric bulk


  • Large elution time difference between toluene and bromobenzene

Ethyltoluenes and Cumene Purifications

  • ONC materials demonstrate separation capability for a wide range of industrially relevant chemicals


  • Shown here is the separations of ethyltoluenes along with cumene from its byproducts


  • ONC-based chromatographic system is expanding into separation of a variety of functionalized aromatics ranging from petrochemicals to flavorings and fragrance molecules

C02 Capture

  • ONC crystals have very high selectivity for CO2 (3000:1 over CH4)


  • The high selectivity for CO2 coupled with reversible absorption and release make ONC porous materials ideal for use in CO2 capture and recycle

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