Light atmospheric distillation column

In present-day refineries, the fluid catalytic cracking (FCC) unit has become the major gasoline-producing unit. The FCC s major purpose is to upgrade heavy fractions, that is, gas oil from the atmospheric and vacuum distillation columns and delayed coker, into light products. Atmospheric gas oil has a boiling range of between 650-725°F.9... 

Before the reaction was started the air was displaced from the reaction system with argon. A solution of diphenyldiazomethane (10.5 g, 54 mmol) in freshly distilled butyl vinyl ether (50 mL) was then added drop-wise to a boiling solution of anhyd CuSO (0.3026 g, 1.90 mmol) in butyl vinyl ether (100 mL) with stirring for 4 h. When no more Nj was liberated (780 mL, 64.5yo), the mixture was cooled (in an atmosphere of argon) and the catalyst filtered off. Butyl vinyl ether was distilled off under vacuum and the resulting residue, after separation of benzophenone azine which had crystallized out, was fractionated under vacuum. A light-yellow distillate (11.1 g bp 133-155 C/0.2 Torr), which was a mixture of l-butoxy-2,2-diphenyl-cyclopropane (1), benzophenone azine (2) and benzophenone (3), was obtained. The cyclopropyl ether was isolated from this mixture by means of column chromatography (alumina activity II, hexane/EtjO 10 1) and was finally purified by vacuum distillation yield 2.36g (16%) bp 78 - 79°C/0.015 Torr. 

Energy consumption of the rectification process is reduced via integrated atmospheric and vacuum rectification as well as optimal utilization and operation of heat flows. MIDER claims to save some 50,000 tons of fuel oil per annum compared with a traditional distillation process. The process is characterized by the use of five instead of the usual two distillation columns. The process development was based on the objective of avoiding unnecessary overheating of the light components. Additionally, it avoids degrading the thermal levels associated with the drawing off of heavy fractions. 

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. 

Bottoms and three side-cut strippers remove light ends from products and may utilize steam or reboilers. In Fig. 13-92 a reboiled stripper is utilized on the light distillate, which is the largest side cut withdrawn. Steam-stripping rates in side-cut strippers and at the bottom of the atmospheric column may vary from 0.45 to 4.5 kg (1 to 10 lb) of steam per barrel of stripped liquid, depending on the fraction of stripper feea hquid that is vaporizea. 

Figure 6. Block drawing of the pilot installation for the production of trichloromethyl chloroformate by exhaustive photochlorination [39] 1 Dryer for gaseous Cl2 (H2S04 cone.). 2 Safety tank. 3 Thermoregulated immersion-type photochemical reactor. 4 Raschig column. 5 Cl2 detection system (1,2,4-trichlorobenzene). 6 Neutralization tank (20% NaOH). 7 Reservoir of 20% NaOH. 8 Buffer to atmospheric pressure (20% NaOH). 9 Active carbon filter. 10 Reservoir of crude trichloromethyl chloroformate. 11 Buffer to normal atmosphere via CaCl2 filter and direct entry for trichloromethyl chloroformate to be distilled. 12 Distillation flask with Vigreux column. 13 Exit to vacuum pump. 14 Solid NaOH filter before pump. 15 Cooling water alarm linked to power supply of the light source. 16 Medium pressure mercury arc. 17 Heater for distillation apparatus. 18 Magnetic stirrers. /T thermometer /P manometer.

After the autoclave was cooled, the contents were transferred to a round-bottomed flask equipped with a Claisen-type distillation head. In the early runs, the crude oils were filtered to remove catalyst and other solids. The filtration was slow and difficult. We soon found that the filtration step was not necessary, and the solids were left in the oil. Distillation of the crude oil at atmospheric pressure gave water and light oils. The pressure was then reduced to about IS mm., and everything that would distill was collected. The distillate was then fractionally distilled at atmospheric pressure through a 30-in. Vigreaux column and, at first, four fractions were collected ... 

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