Hydrogen oxygen/nitrogen/sulfur content

Figure 5. Hydrogen/oxygen/nitrogen/sulfur content vs. severity...

The composition of coal is conveyed by representing its proximate and ultimate analysis. The former implies determination of contents of moisture, volatile matter, fixed carbon, and ash, while the latter implies total carbon, hydrogen, oxygen, nitrogen, sulfur and ash. Here, an account will be provided of the constituents of coal, moisture, volatile matter, ash, fixed carbon, and some miscellaneous components. 

Elemental analysis of fuel oil often plays a more major role that it may appear to do in lower-boiling products. Aromaticity (through the atomic hydrogen/carbon ratio), sulfur content, nitrogen content, oxygen content, and metals content are all important features that can influence the use of residual fuel oil. 

The ultimate chemical analysis of contents (wt%) of hydrogen, carbon, nitrogen, sulfur with oxygen determined by difference. 

Wool is a protein fiber consisting of the chemical elements carbon, hydrogen, oxygen, nitrogen, and sulfur (Table 2.4, Fig. 2.16). The high content of sulfur in wool results from the high content of cysteine, an amino acid with two sulfur atoms in a disulfide bond. 

The metal content in the complexes is estimated by standard volumetric and gravimetric methods. Of late, the elemental composition of hydrazine species is evaluated with a CHNS/O micro-analyzer for nitrogen, hydrogen, carbon, oxygen, and sulfur content. Metal content is evaluated by inductively coupled plasma optical emission spectroscopy (ICP-OES). 

Solid fuels, unlike gases and liquids, are entirely characterized by their composition. For example, coal can be characterized by its carbon, hydrogen, oxygen, sulfur, and nitrogen content. The water and mineral content of coal are also important means of differentiating coals from various sources. 

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. 

In terms of the elemental composition of petroleum, the carbon content is relatively constant it is the hydrogen and heteroatom contents that are responsible for the major differences. Nitrogen, oxygen, and sulfur are present in only trace amounts in some petroleum, which thus consists primarily of hydrocarbons. On the other hand, a crude oil containing 9.5% heteroatoms may contain essentially no true hydrocarbon constituents insofar as the constituents contain at least one or more nitrogen, oxygen, and/or sulfur atoms within the molecular structures. 

In this chapter, the biogeochemical cycling of organic matter is discussed from the perspective of its carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur content. 

Typically, liquids derived from coal are lower in hydrogen content and contain more impurities than do petroleum products. These impurities consist of atoms other than hydrogen and carbon, that is, nitrogen, sulfur, oxygen, and inorganic materials. Upgrading of coal liquids to make specification fuels typically involves both hydrogen addition and removal of impurities. 

For simplicity, coal is assumed to be constituted from carbon, hydrogen and oxygen. This assumption may be valid since nitrogen and sulfur contents are relatively small and their contribution to Hf° and S° may be neglected. 

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