Oxygen content asphalt

Oxygen is one of the five (C, H, N, O, and S) major elements in resids and asphalt, although the level rarely exceeds 1.5% by weight. Many petroleum products do not specify a particular oxygen content, but if the oxygen compounds are present as acidic compounds such a phenols (Ar-OH) and naphthenic acids (cycloalkyl-COOH), they are controlled in different specifications by a variety of tests. 

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... 

The oxygen content of crude oil is typically low and is usually in the form of naphthenic acid compounds. Asphaltic crudes can contain significantly more of these acids than paraffinic crude oils. Also, the concentration of oxygen increases with the boiling point of the crude oil fraction. 

The inter-molecular interactions are primarily the weak van der Waal s and aromatic 7T bonding dipole-dipole interactions. Flydrogen bonding and acid-base interactions are only prevalent in the heavier materials such as redidual (asphaltic) materials where the nitrogen and oxygen content is high. Processed material has... 

All crudes are a variation of the hydrocarbon base CH2. The ultimate composition shows 84 to 86% carbon, 10 to 14% hydrogen, and small percentages of sulfur (0.06 to 2%), nitrogen (2 %), and oxygen (0.1 to 2%). The sulfur content is usually below 1.0% but may be as high as 5.0%. Physically crude oil may be water-white, clear yellowish, green, brown, or black, heavy and thick like tar or asphalt. 

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. 

The sulphur content of coals, oils, tars, asphalts, etc., may be determined by combustion in an oxygen bomh, a little ammonium nitrate being added to the charge to ensure complete oxidation to sulphuric acid (see p. 136).5 After washing out the bomb the sulphur is determined as barium sulphate. 

Generally, most asphalt is 79-88% w/w carbon, 7-13% w/w hydrogen, trace-8% w/w sulfur, 2-8% w/w oxygen, and trace-3% w/w nitrogen.Trace metals such as iron, nickel, vanadium, calcium, titanium, magnesium, sodium, cobalt, copper, tin, and zinc occur in crude oils. Vanadium and nickel are bound in organic complexes and, by virtue of the concentration (distillation) process by which asphalt is manufactured, are also found in asphalt. The catalytic behavior of vanadium has prompted studies of the relation between vanadium content and an asphalt s sensitivity to oxidation (viscosity ratio).The significance of metals in the behavior of asphalts is not yet well understood or defined. 

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