Hydrogen nitrogen-oxygen mixtures

The fields in which the thermobalance can be applied depend on the possibilities of varying the conditions which affect the sample. The course of the reaction is particularly dependent on the ambient atmosphere and pressure. In the case of the balance design shown, it is possible to operate not only in a flow of air, but also in other defined atmospheres such as hydrogen, nitrogen, oxygen or gas mixtures. 

Elemental analyses of petroleum show that it contains mainly carbon and hydrogen. Nitrogen, oxygen, and sulfur (heteroelements) are present in smaller amounts, and trace elements such as vanadium, nickel, etc, are also present. Of the heteroelements, sulfur is the most important. The mixture of hydrocarbons is highly complex. Paraffinic, naphthenic, and aromatic structures can occur in the same molecule, and the complexity increases with boiling range. The attempted classification of crude oils in terms of these three main structural types has proved inadequate. 

The fluids contained within petroleum accumulations are mixtures of organic compounds, which are mostly hydrocarbons (molecules composed of hydrogen and carbon atoms), but may also include sulphur, nitrogen, oxygen and metal compounds. This section will concentrate on the hydrocarbons, but will explain the significance of the other compounds in the processing of the fluids. 

The situation does not improve with mixtures with the hydrides of the elements. Thus, a detonation occurred during contact between water and chlorine due to an accidental spark. Phosphine, silane and diborane all combust spontaneously in chlorine (their behaviour is the same in oxygen). With hydrogenated nitrogenous compounds ammonia, hydrazine, hydroxylamine, ammonium salts (especially ammonium chloride), and also sulphamic acid (these last two in an acid medium) there is ignition or even detonation. 

Pre-addition of nitrogen oxide (or nitrosyl chloride as its precursor) to stoicheio-metric hydrogen-oxygen mixtures at 240 mbar/360°C will cause immediate ignition under a variety of circumstances. 

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