High-pressure gaseous hydrocarbon

A leak of high-pressure gaseous hydrocarbon can, if it ignites inunediately, produce a jet fire that can impinge on other process plant and then escalate to become a large conflagration, in a similar fashion to the Piper Alpha accident. (Chapter 13)... 

An un-ignited leak of high-pressure gaseous hydrocarbon can quickly generate a large, inflammable cloud which may drift until it finds an ignition source, and it can then yield a vapor cloud explosion, as happened at Buncefield. (Chapter 6)... 

Natural gas, found in geological accumulations, normally refers to the gaseous fossil-based equivalent of oil. Its composition varies widely, from high concentrations of nitrogen and carbon dioxide to (almost) pure methane. In general, it contains low concentrations of the higher (saturated) hydrocarbons, which influence the physical properties and may present condensation problems in high-pressure transport lines. 

As one more common example of liquid fuels present reference may be drawn to liquified petroleum gas (LPG) or bottled gas or refinery gas. This fuel is obtained as a by-product during the cracking of heavy oils or from natural gas. It is dehydrated, desulfurized and traces of odours organic sulfides (mercaptans) are added in order to identify whether a gas leak has occurred. Supply of LPG is carried out under pressure in containers under different trade names. It consists of hydrocarbons of great volatility such that they can occur in the gaseous state under atmospheric pressure, but are readily liquifiable under high pressures. The principal constituents of LPG are n-butane, iso-butane, butylene and propane,... 

Gaseous non-polar and hydrocarbon mixtures at high pressures... 

Figure 17.14. Some unusual reactor configurations, (a) Flame reactor for making ethylene and acetylene from liquid hydrocarbons [Patton et al., Pet Refin 37(li) 180, (1958)]. (b) Shallow bed reactor for oxidation of ammonia, using Pt-Rh gauze [Gillespie and Kenson, Chemtech, 625 (Oct. 1971)]. (c) Sdioenherr furnace for fixation of atmospheric nitrogen, (d) Production of acetic acid anhydride from acetic acid and gaseous ketene in a mixing pump, (e) Phillips reactor for low pressure polymerization of ethylene (closed loop tubular reactor), (f) Polymerization of ethylene at high pressure.

Cassel s results indicate gaseous films, the hydrocarbons giving the same direction of curvature as above, i.e. a preponderance of the 6 correction in the van der Waals type of equation but the lower alcohols and nitromethane showed opposite curvature in the F-p2 curves, except at very high pressures this indicates strong lateral adhesion the F-A relations for the adsorbed films, deducible from his results, indicate association into double molecules even at great dilutions. Butyl and iso-amyl alcohols formed adsorbed films intermediate in properties between the lower alcohols and the hydrocarbons. No lowering of tension at all was observed with water. Cassel s results differ considerably from those of other workers since the surface tension of his supposedly clean mercury was some 25 dynes lower than the best values of several other workers, and since no adsorption of water was found, there may have been a considerable amount of contamination initially on the mercury. 

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