The fuels redined from crude oil can be divided into two general types: 1. Fuels that are exploded, when vaporized with air, to provide primary moving power, and 2. Those fuels that are either burned directly for heat and light or are converted into secondary energy sources such as electricity. The former type includes the aviation fuels ( Avgas, Avtag, Avtur), industrial and domestic gases ( LPG), motor spirits, diesel oil, and refinery gases. Fuels of the latter type include the ordinary kerosene and the various grades of fuel oils.
In the 1860s, when modern refinery practices began, the main products from raw petroleum were lamp kerosene and residue for use as a lubricant. Nowadays however, as we have already seen, about 88% of all crude oil ends up as fuel of one kind or another. Considering only the finite nature of fossil fuels, many people feel that far too much oil is being burned needlessly.
Of the ramaining 12%, just over half is refined into petroleum-chemical intermediates. These are used as feedstock in the manufacture of synthetic materials ( fibres, rubbers, plastics, etc.), fertilizers, insecticides, and even protein for animal feeds. A molecule of vinyl chloride is produced by cracking ethylene dichloride, which is a compound made by reaching ethylene and chlorine. In the catalytic conversion process known as polymerization, vinyl chloride becomes the well-known oil-based plastic, PVC ( polyvinyl chloride).
About 5% of the average barrel of crude is used in the production of a wide range of lubricating oils and greases, waxes, solvents, and asphalt for roads and weatherproofing. Finally, there are commercial markets for the by-products of many refinery processes, examples of these are pure sulphur, important in other areas of industry, and the platinum in some spent catalysts.