Vacuum distillation fractionator selection

TBT of mark tch , is used which was distiled in vacuum, three times selecting fraction with boiling temperature 7j,=430-432 K at pressure 1,33 Gpa [6]. Obtaited by such method fraction was preserved under molecular sieve 4 A. 

A middle CCB-distillate fraction (420-520°C/760 mm Hg) was produced by a high vacuum distillation (0.5-1.0 mm Hg 15/5 column). The CCB feed was selected carefully, only CCB feed with high aromaticity (aromatic carbon=65-73 atom %), which was produced from a high severity catalytic cracking operation, was used. 

The solution from the extractors is vacuum-distilled and the solvent recovered. The remaining terpene oils are fractionally re-distilled under vacuum and recovered as turpentine, dipentene, and pine oil. The nonvolatile rosin is of dark color and is upgraded by clarification methods, such as selective absorption of its solution (bed-filtering). 

A more recent test method (ASTM D-5236) is seeing increasing use and appears to be the method of choice for crude assay vacuum distillations. Wiped-wall or thin-fihn molecular stills can also be used to separate the higher-boiUng fractions under conditions that minimize cracking. In these units, however, cut points cannot be directly selected because vapor temperature in the distillation column cannot be measured accurately under... 

It is, of course, possible to combine GTA and the various inclusion techniques with mild vacuum distillation to form fractions of less complexity. One can apply selective detectors in each chromatographic method, tracing a pseudo-GTA profile. These methods, sometimes called electronical sieving, will be discussed in Section VI. It is also possible to use high-resolution MS (HR-MS) for type analysis of complex hydrocarbon mixtures. Teeter reviewed the methods employed until 1985, showing that the relative amount of classes of compounds in a mixture can be obtained by HR-MS. 

Cmde is distilled and the bottoms, atmospheric resid, is sent to a vacuum distillation unit (VDU) sometimes called a vacuum pipestill (VPS) for further fractionation. Vacuum fractionation is used to separate the atmospheric resid into several feed streams or distillates. Conventional solvent processing uses selected solvents in physical processes to remove undesirable molecules... 

Solvent deasphalting. This is an extraction of the heaviest fractions of a vacuum residue or heavy distillate. The extract is used to produce the bitumen. The separation is based on the precipitation of asphaltenes and the dissolution of the oil in an alkane solvent. The solvents employed are butane or propane or a butane-propane mixture. By selecting the proper feedstock and by controlling the deasphalting parameters, notably temperature and pressure, it is possible to obtain different grades of bitumen by this process. 

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. 

Reaction conditions were 200 °C or less and at least 200 atm of carbon monoxide. Benzene, chlorobenzene, cyclohexane, or 1,1,2-trichloro-1,2,2-trifluoroethane were used as solvents. The noble metal could be supported, but even unsupported or in the form of salt, oxide, or complex. Among the Lewis acid cocatalysts used successfully were FeCU, FeCU, FeBrs, AICI3, AlBrs, SnCl4, CuCL, and anhydrous HCl, but the highest yields were obtained with supported metals and with FeCL as cocatalyst. The presence of FeCL allowed for the use of milder experimental conditions with respect to the monometallic system, also affording higher conversions and better selectivities [24-26]. For example, nitrobenzene (24.6 g), Rh/C (5 % on Rh, 5.0 g), anhydrous ferric chloride (0.4 g), under 500 atm of carbon monoxide and at 190 °C for 5.5 h in benzene (100 ml), gave 100 % conversion with formation of PhNCO (35 % after vacuum fractional distillation). Diphenylurea, PhNHC(0)NHPh, and 1,3,5-... 

Three methods widely used for the production of deterpenated oils are fractional distillation under vacuum selective extraction of the soluble oxygenated compounds in diluted alcohol, and chromatography using sihca-gel. 

Recently, major synthetic oil producers in Western Canada have switched from atmospheric bottoms to vacuum resids for processing bitumen. This raises the question of what impact this change might have on the coke induction period during thermal processing of these materials. To address this question, Athabasca bitumen (+343°C) was fractionated using Distact distillation into four distillates and resids.The selected boiling point cuts were 525°C, 575°C, 625°C, and 675°C. The coke induction periods of bitumen... 

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