Fractional distillation description

Fluorine [7782-41-4] M 38.0, b -129.2 . Pass the gas through a bed of NaF at 100° to remove HF and SiF4. [For description of stills used in fractional distillation, see Greenberg et al. / Phys Chem 65 1168 196P, Stein et al. Purification of Fluorine by Distillation, Argonne National Laboratory, ANL-6364 1961 (from Office of Technical Services, US Dept of Commerce, Washington 25).] HIGHLY TOXIC. 

Forms of Still-head for Fractional Distillation, with a Description of some New Forms possessing Special Advantages, Trans. Chem. Soc., 1899, 75, 679. 

For Berthelot, the chemical formula of a compound does not serve as a description of a hypothetical molecular reality it is the result of an action, and offers a precis of the synthetic process, what he termed a generative equation . Thus, Berthelot concluded that benzene was an isomer of acetylene because, when heated to 600°C, acetylene produced a liquid containing traces of benzene, which he could isolate by fractional distillation. Nevertheless, this strategy had little future. By contrast, the chemists who based their research on August von Kekule s hypothesis concerning the structure of the benzene molecule were able to produce a cornucopia... 

Several descriptions have been pubUshed of the continuous tar stills used in the CIS (9—11). These appear to be of the single-pass, atmospheric-pressure type, but are noteworthy in three respects the stills do not employ heat exchange and they incorporate a column having a bubble-cap fractionating section and a baffled enrichment section instead of the simple baffled-pitch flash chamber used in other designs. Both this column and the fractionation column, from which light oil and water overhead distillates, carboHc and naphthalene oil side streams, and a wash oil-base product are taken, are equipped with reboilers. 

Irreversible processes are mainly appHed for the separation of heavy stable isotopes, where the separation factors of the more reversible methods, eg, distillation, absorption, or chemical exchange, are so low that the diffusion separation methods become economically more attractive. Although appHcation of these processes is presented in terms of isotope separation, the results are equally vaUd for the description of separation processes for any ideal mixture of very similar constituents such as close-cut petroleum fractions, members of a homologous series of organic compounds, isomeric chemical compounds, or biological materials. 

Description Polymer-grade ethylene is oligomerized in the liquid-phase reactor (1) with a catalyst/solvent system designed for high activity and selectivity. Liquid effluent and spent catalyst are then separated (2) the liquid is distilled (3) for recycling unreacted ethylene to the reactor, then fractionated (4) into high-purity alpha-olefins. Spent catalyst is treated to remove volatile hydrocarbons and recovered. The table below illustrates the superior purities attainable (wt%) with the Alpha-Select process ... 

Description Extractive distillation is used to separate close-boiling components using a solvent that alters the volatility between the components. An ED Sulfolane unit consists of two primary columns they are the ED column and the solvent recovery column. Aromatic feed is preheated with lean solvent and enters a central stage of the ED column (1). The lean solvent is introduced near the top of the ED column. Nonaromatics are separated from the top of this column and sent to storage. The ED column bottoms contain solvent and highly purified aromatics that are sent to the solvent recovery column (2). In this column, aromatics are separated from solvent under vacuum with steam stripping. The overhead aromatics product is sent to the BT fractionation section. Lean solvent is separated from the bottom of the column and recirculated back to the ED column. 

Description Aromatics are produced from naphtha in the Aromizing section (1), and separated by conventional distillation. The xylene fraction is sent to the Eluxyl unit (2), which produces 99.9% paraxylene via simulated countercurrent adsorption. The PX-depleted raffinate is isomerized back to equilibrium in the isomerization section (3) with either EB dealkylation-type (XyMax) processes or EB isomerization-type (Oparis) catalysts. High-purity benzene and toluene are separated from non-aromatic compounds with extractive distillation (Morphylane ) processes (4). Toluene and C9 to Cn aromatics are converted to more valued benzene and mixed xylenes in the TransPlus process (5), leading to incremental paraxylene production. 

Description To produce DC PD and isoprene, pygas is depentanized and the C5 fraction is processed thermally to dimerize cyclopentadiene to DCPD which separates easily (1) from the C5s via distillation. Isoprene can be recovered by extractive distillation and distillation. The remaining C5s and the C6-C9 cut are fed to the first stage (2) catalytic hydrogenation unit where olefins and diolefins are eliminated. 

Description EB is dehydrogenated to styrene over potassium promoted iron-oxide catalyst in the presence of steam. The endothermic reaction is done under vacuum conditions and high temperature. At 1.0 weight ratio of steam to EB feed and a moderate EB conversion, reaction selectivity to styrene is over 97%. Byproducts, benzene and toluene, are recovered via distillation with the benzene fraction being recycled to the EB unit. 

Description The alkylator (1) and benzene stripper (2) operate together as a distillation column. Alkylation and distillation occur in the alkylator (1) in the presence of a zeolite catalyst packaged in patented structured packing. Unreacted ethylene and benzene vapor from the alkylator top are condensed and fed to the finishing reactor (3) where the remaining ethylene reacts over zeolite catalyst pellets. The benzene stripper bottoms is fractionated (5 6) into EB prod-... 

For phase partitioning (equilibrium), the variable of interest is the solute concentration in the first phase that would be in equilibrium with the solute concentration in a second phase. For example, in the distillation example above, each component is partitioned between the vapor and liquid phases. The mathematical description of the equilibrium relationship is usually given as the concentration in one phase as a function of the concentration in the second phase as well as other parameters. Some examples are the Henry s Law relation for the mole fraction of a solute in a liquid as a function of the mole fraction of the solute in the gas phase which contacts the liquid ... 

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