A theoretical study of the subclass 2.1 hazardous goods properties - hydrocarbon gases to prevent the risks of developing man-made emergencies in rail transport

Hydrocarbon gaseous compounds play important role in the modern economy of the early 21^st century. The global annual production of natural hydrocarbons amounts to an impressive 4.10¹² m³. They are used as energy carriers, raw materials for the production of organic and inorganic substances, materials, products, and in other areas. All types of transport are used for the transportation of hydrocarbon gases (in various physical states, such as compressed, liquefied, or dissolved). This work focuses on rail transport; loading of liquefied hydrocarbon gases in 2025 is estimated at 13.4 million tons. The main volume is carried by pipeline transport, but marine, river, road, and, to a lesser extent, air transport also play a significant role.

Low-molecular hydrocarbon compounds, including 24 nomenclature positions of individual compositions, have been classified by the UN ECOSOS Committee of Experts on the Transport of Dangerous Goods and in accordance with the Globally Harmonized System of Classification and Labelling of Chemicals as dangerous goods of Class 2 (gases) and subclass 2.1 (flammable gases). Alongside their useful consumer properties, combustibility, and high calorific value, hydrocarbon gases have the potential for explosion and explosive transformation under difficult-tocontrol conditions. The manifestation of this property during transport poses a significant hazard, which is reflected in the prohibition of shunting tank cars with such cargoes from hump yards. The prohibition of shunting significantly reduces the technical and economic performance of classification yards.

This work is a continuation of research conducted at the university from 2005 to 2010 under contracts with Russian Railways. At present, the problem has not lost its relevance and continues to attract the attention of industry specialists. This work is devoted to studying the characteristics of cargo, primarily identifying the patterns of explosion and combustion of hydrocarbon gases, and attempting to differentiate conditions ‘by degree of danger’. In a series of studies, we plan to examine the influence of factors such as structural, thermodynamic, kinetic, phenomenological, environmental, and economic on the course and outcome of reactions; to search for the least dangerous gases and the least hazardous conditions for preparing an experimental program, first numerical, then full-scale, for the unloading of tank cars from hump yards. It should be noted that there is also a prohibition on unloading empty tank cars that previously carried hydrocarbon gases from hump yards.

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