Hydrocarbons packing

The bonded hydrocarbon packings...are very hydrophobic...Therefore, in reversed phase separations...it is desirable to use aqueous mobile phases containing > 10% of a miscible organic solvent...to improve wetting characteristics. Mobile phases with no or low concentrations of organic solvent produce broad peaks because of the slow equilibrium resulting from the resistance to solute mass transfer across the interface of the two very unlike phases."... 

Malcolm, B. A. et al. (1990). Ancestral lysozymes reconstructed, neutrality tested, and thermostability linked to hydrocarbon packing. Nature, 345, 86-9. 

Takeuchi et al. Styrene oligomers and polyaromatic hydrocarbons Packed capillary column ODS-SC-015/im 150 X 0.34/ m Carbon dioxide uv Pressure program... 

This type of analysis requires several chromatographic columns and detectors. Hydrocarbons are measured with the aid of a flame ionization detector FID, while the other gases are analyzed using a katharometer. A large number of combinations of columns is possible considering the commutations between columns and, potentially, backflushing of the carrier gas. As an example, the hydrocarbons can be separated by a column packed with silicone or alumina while O2, N2 and CO will require a molecular sieve column. H2S is a special case because this gas is fixed irreversibly on a number of chromatographic supports. Its separation can be achieved on certain kinds of supports such as Porapak which are styrene-divinylbenzene copolymers. This type of phase is also used to analyze CO2 and water. 

Firestone at al. " demonstrated the importance of solvent density in the special case of intramolecular Diels-Alder reaction in highly viscous media. Efficient packing of the hydrocarbon solvent was... 

Potassium Methylate. Potassium methoxide [865-33-8] KOCH, mol wt 70.13, is a fine, free-flowing, yellowish-white, caustic, hygroscopic powder purity 96.5—99% powder density after loose shaking, 0.75 g/mL apparent density (packing weight), 1.00 g/mL medium grain size, 0.05 —0.8 mm easily soluble in alcohols (33% in methanol at 20°C), insoluble in hydrocarbons. 

Cehte or firebrick packing for glc columns is often treated with TMCS, DMCS, or other volatile silylating agents (see Table 1) to reduce tailing by polar organic compounds. A chemically bonded methyl siUcone support is stable for temperature programming to 390°C and allows elution of hydrocarbons up to C q (20). 

The Phillips Steam Active Reforming (STAR) process catalyticaHy converts isobutane to isobutylene. The reaction is carried out with steam in tubes that are packed with catalyst and located in a furnace. The catalyst is a soHd, particulate noble metal. The presence of steam diluent reduces the partial pressure of the hydrocarbons and hydrogen present, thus shifting the equHibrium conditions for this system toward greater conversions. 

For ordered, or structured, packings, pressure-drop estimation methods have been reviewed by Fair and Bravo [Chem. Eng. Progr, 86(1), 19 (1990)]. It is not common practice to use the packing factor approach for predicling pressure drop or flooding. For operation below the loading point, the model of Bravo et [Hydrocarbon... 

By far the greatest number of instaUations is for the removal or recoveiy of mostly small concentrations of acidic and other components from air, hydrocarbons, and hydrogen. Hundreds of such plants are in operation, many of them of great size. They mostly employ either packed or tray towers. Power requirements for such equipment are small. When the presence of solid impurities could clog the equipment or when the pressure drop must be low, spray towers are used in spite of their much larger size for a given capacity and scrubbing efficiency. 

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