Oxygen condensers, condensate content

The composition of crude oil may vary with the location and age of an oil field, and may even be depth dependent within an individual well or reservoir. Crudes are commonly classified according to their respective distillation residue, which reflects the relative contents of three basic hydrocarbon structural types paraffins, naphthenes, and aromatics. About 85% of all crude oils can be classified as either asphalt based, paraffin based, or mixed based. Asphalt-based crudes contain little paraffin wax and an asphaltic residue (predominantly condensed aromatics). Sulfur, oxygen, and nitrogen contents are often relatively higher in asphalt-based crude in comparison with paraffin-based crudes, which contain little to no asphaltic materials. Mixed-based crude contains considerable amounts of both wax and asphalt. Representative crude oils and their respective composition in respect to paraffins, naphthenes, and aromatics are shown in Figure 4.1. 

Powdered niobium metal, 20.0 g. (—200 mesh), and tin(II) fluoride, 52.0 g. (40 mesh),t are mixed in a molybdenum crucible in an Inconel- or nickel-pipe reactor approximately 3 in. in diameter and 10 in. long and heated to 400-500°C. in a stream of dry nitrogen. The niobium(V) fluoride volatilizes from the reaction mixture and condenses on the water-cooled lid of the reactor, which leaves metallic tin in the crucible. The yield of niobium(V) fluoride is 21.1 g., or 95% of theoretical. A very small amount of blue niobium oxyfluoride (composition of variable oxygen and fluorine content) often forms as an impurity because of the presence of minute amounts of oxygen. Anal. Calcd. for NbFs Nb, 49.44 F, 50.56. Found Nb, 49.43 F, 50.2. 

Cap Gas. Both crude and asphaltene-free oil were used to determine the consequences of low-temperature oxidation. It was found that the oxygen content in an artificial gas cap was completely consumed by chemical reactions (i.e., oxidation, condensation, and water formation) before the asphaltene content had reached equilibrium. 

The error introduced by Reaction 3 was further diminished by flushing out much of the oxygen from the refluxing system by boiling the contents before adding the potassium iodide. Crystals between 2 and 5 mm. were used because smaller ones had a tendency to stick to the walls of the wet condenser. Early in this work it was noticed that crystals of potassium iodide which were not washed down were often partly oxidized to iodine, which worked down into the flask and caused high results. Thus it was important to wash all the potassium iodide down the condenser with water. Crystals of potassium iodide were used rather than a solution because this avoided the possibility of such a solution being oxidized to contain triiodide ion. 

The material balance is consistent with the results obtained by OSA (S2+S4 in g/100 g). For oil A, the coke zone is very narrow and the coke content is very low (Table III). On the contrary, for all the other oils, the coke content reaches higher values such as 4.3 g/ 100 g (oil B), 2.3 g/ioo g (oil C), 2.5 g/ioo g (oil D), 2.4/100 g (oil E). These organic residues have been studied by infrared spectroscopy and elemental analysis to compare their compositions. The areas of the bands characteristic of C-H bands (3000-2720 cm-1), C=C bands (1820-1500 cm j have been measured. Examples of results are given in Fig. 4 and 5 for oils A and B. An increase of the temperature in the porous medium induces a decrease in the atomic H/C ratio, which is always lower than 1.1, whatever the oil (Table III). Similar values have been obtained in pyrolysis studies (4) Simultaneously to the H/C ratio decrease, the bands characteristics of CH and CH- groups progressively disappear. The absorbance of the aromatic C-n bands also decreases. This reflects the transformation by pyrolysis of the heavy residue into an aromatic product which becomes more and more condensed. Depending on the oxygen consumption at the combustion front, the atomic 0/C ratio may be comprised between 0.1 and 0.3 ... 

Taking this one step further, perhaps even an inorganic gene may have been provided by clay mineral sources. Earliest clay samples are of a mineral called montmorillonite that consists of sheets of aluminosilicates in which Fe2+, Fe3+ and Mg2+ are substituted for some of the Al3+, and Al3+ is substituted for Si4+. The oxygen content of the layers does not change and the alternative valencies allow the production of positive and negatively charged layers. Dramatically, Paecht-Horowitz and co-workers showed that the amino acid adenylate could be polymerised with up to 50 units on the montmorillonite surface in aqueous solution. Similar condensation reactions for carbohydrates on hydrotalcite surfaces have... 

Figure 3. Content of oxygen in condensed phase of burning polypropylene at varying distances below the surface.

Elsewhere in this book, White and Sandel [7] discuss the integration of chlorine and ethylene dichloride (EDC) processes. The oxygen content of the chlorine fed to an EDC unit must be kept within the process specification. This can be achieved by liquefying at least part of the chlorine in order to reject non-condensables or by acidifying the brine fed to the cells. Oxygen results from the anodic oxidation of hydroxide ions free acid in the feed brine will neutralise those ions and so reduce the amount of oxygen formed. 

Potassium perchlorate (KP KCIO4) is a weU-known oxidizer, used as an oxidizer component of black powder. Since KP produces potassium oxides and condensed products, the high molecular mass Mg of the combustion products is not favorable for its use as an oxidizer in rocket propellants. A mixture of 75 % KP with 25 % asphalt pitch was used as a rocket propellant named Galcit, which was the original prototype of a composite propellant in the 1940 s. Potassium chlorate (KCIO3) is also a crystalline oxidizer, and although it has a lower oxygen content compared... 

---