Petroleum Separability Increase

To increase recovery of valuable (light) components, it is necessary to increase the amount of the heat brought in without exceeding the set maximum permissible temperature. There are several methods to achieve this goal  

It is necessary to bring in heat, not in the reboiler of the column, but in its feeding, bringing in the bottom a light stripping agent (most often, steam serves as one). At such a method of creation, vapor flow maximum 

It is necessary to keep in the feed cross-section the lowest possible pressure, which provides the possibility to obtain a maximum fraction of vapor phase in the feeding and a maximum vapor flow rate in the column. 

It is necessary to increase the number of theoretical trays in sections adjacent to feed cross-section, where the most valuable products are being separated from the less valuable ones. 

---

Columns with side stripping sections were used for petroleum separation already in the first decades of twentieth century. This choice is quite grounded by the main purposes of designing increase of separability, and decrease of energy and capital expenditures on separation. 

As the boiling points increase, the cuts become more and more complex and the analytical means must be adapted to the degree of complexity. Tables 3.4 and 3.5 describe the most widely used petroleum product separation scheme and the analyses that are most generally applied. 

The camphorquinone can be purified in either of two ways, (i) To save time, the drained but still damp material can be recrystallised from water containing 10% of acetic acid, the hot filtered solution being cooled and vigorously stirred. The quinone separates as brilliant yellow crystals (yield, 2 5 g.), m.p. 192-194 , increased to 196-197 by a second reciystal-lisation. (ii) The crude camphorquinone can be dried in a vacuum desiccator (weight of dry quinone, 5 g.), and then recrystallised from petroleum (b.p. 100-120 ), the hot solution being filtered through a fluted paper in a pre-heated funnel. The quinone separates in beautiful crystals, m.p. 196-197 , 2 8 g. 

Polymerization in Hquid monomer was pioneered by RexaH Dmg and Chemical and Phillips Petroleum (United States). In the RexaH process, Hquid propylene is polymerized in a stirred reactor to form a polymer slurry. This suspension is transferred to a cyclone to separate the polymer from gaseous monomer under atmospheric pressure. The gaseous monomer is then compressed, condensed, and recycled to the polymerizer (123). In the Phillips process, polymerization occurs in loop reactors, increasing the ratio of available heat-transfer surface to reactor volume (124). In both of these processes, high catalyst residues necessitate post-reactor treatment of the polymer. 

Vacuum Distillation - Heavier fractions from the atmospheric distillation unit that cannot be distilled without cracking under its pressure and temperature conditions are vacuum distilled. Vacuum distillation is simply the distillation of petroleum fractions at a very low pressure (0.2 to 0.7 psia) to increase volatilization and separation. In most systems, the vacuum inside the fractionator is maintained with steam ejectors and vacuum pumps, barometric condensers, or surface condensers. 

Many of the phenols which are used in household and other commercial disinfectant products are produeed from the tar obtained by distillation of coal or more recently petroleum. They are known as the tar acids. These phenols are separated by fractional distillation according to their boiling point range into phenol, cresols, xylenols and high boiling point tar acids. As the boiling point increases the properties of the products alter as shown ... 

The most common mobile phase is a gradient of petroleum ether or hexane with increasing concentrations of acetone or diethyl ether. Development of the column should be optimized for each sample to afford a quick and effective separation to avoid band broadening. The separation can be followed visually. The most non-polar a- and 3-carotenes are eluted first as a yellow band followed by the chlorophylls and other more polar carotenoids like cryptoxanthin, lutein, and zeaxanthin that frequently fuse together and appear as a single band. ... 

In the processing of petroleum the first step is the removal of salt water. The presence of salt water in any processing steps would mean that expensive corrosion-resistant materials are required for those steps. This would greatly increase the price of the equipment (see Chapter 9). After removing the salt water, the next major separation is the crude still where the feed is split into six or more large-volume streams to reduce the size of future processing equipment. 

The partition of different lipids between two immiscible solvents (countercurrent distribution) is useful for crude fractionation of lipid classes with greatly differing polarities. Repeated extractions in a carefully chosen solvent pair increase the effectiveness of the separation but in practice mixtures of lipids are still found in each fraction. A petroleum ether-ethanol-water system can be used to remove polar contaminants (into the alcoholic phase) when interest lies in the subsequent analysis of neutral glycerides, which may be recovered from the ether phase. Carbon... 

The double bond difference between the olefins and the paraffins is the quintessential difference between the petrochemicals and petroleum products— the petrochemicals industry depends much more on the chemical reactivity of the double-bonded molecules. While paraffins can be manipulated in refineries by separation or reshaping, olefins in a petrochemical plant are usually reacted with other organic compounds or another kind of atom or compound such as oxygen, chlorine, water, ammonia, or more of itself. The results are more complicated compounds useful in an increasing number of chemical applications. More on this in later chapters. 

---