About petroleum
Since 1859 petroleum has been one of the most important minerals. While crude oil was initially processed only on lamps of kerosene, today it provides us with an ever-expanding range of products that we can no longer do without.
We are not yet sure about the origin of petroleum, it probably owes its origin to fatty and waxy products from the plant kingdom, which were slowly converted into hydrocarbons over thousands of centuries under high pressure and at a higher temperature. In addition to petroleum, one also finds porous slates soaked with oil, asphalt and here and there small amounts of earth wax.
The crude oil is distilled, usually giving off gases first, followed by light and heavy grades of gasoline, finally lamp kerosene; the last quantities only distill at very high temperatures, where they are partially decomposed. The lubricating oil is now obtained from these high-boiling components, for which certain contaminants must first be removed. There are several methods for refining. The most beautiful method is that of Edleanu, in which liquid sulfurous acid is used to remove the unsaturated hydrocarbons that later cause the decomposition of the lubricating oil.
The purified oil is then distilled in vacuo and with superheated steam.
The non-distillable residues are further processed in other ways as gold iron or petroleum asphalt. By passing the higher boiling components through hot tubes, the large molecules are broken down into smaller ones, cracked, and lower boiling hydrocarbons are obtained. According to this method it is possible to make gasoline from lubricating oil. In addition, it is again possible to make high-boiling saturated hydrocarbons from low-boiling unsaturated hydrocarbons by heating them with certain substances. According to this method, since the unsaturated hydrocarbons can be made from coke or coal, it is also possible to make lubricating oil from coal.
Furthermore, in recent years it has also been possible to make products from coal by reduction with hydrogen, which can be processed on lubricating oil and on petrol. This semi-synthetic lubricating oil has particularly good properties and can be used for many purposes.
Since the possibility cannot be ruled out that the amount of petroleum that we can extract every year becomes less than the amount we need, the extraction of gasoline and lubricating oil from coal is of the utmost importance. In addition, large quantities of volatile hydrocarbons and paraffin can be obtained from peat and lignite. The modern chemical industry is thus able to produce from the raw materials available those products which humanity needs.
The gases escaping from many petroleum sources contain hydrocarbons which can be converted into higher alcohols with the aid of chlorine in other substances. These alcohols are used in large quantities as solvents for lacquers, especially after they have been fortified with acids. Thus, from the first simple distillation of crude petroleum, a chemical industry has grown, the future development of which cannot yet be foreseen.
While by far the largest part of the lubricants used is covered by mineral oil, ie by petroleum products, vegetable and animal oils are still required for a large number of special products.
The vegetable and animal oils, which therefore consist of esters of glycerin and fatty acid, can be mixed with ordinary lubricating oil after a certain pre-treatment. Especially for oil that must be able to withstand high temperatures, such as cylinder oil, both types of oil are mixed and compounded.
