Outline:
- What is petrol? Meaning of name.
- Where obtained, and how?
- Processes of manufacture.
- Uses and commercial importance.
Petroleum is a very important mineral oil in our times. The Latin word petra means “a rock”, while oleum is “oil”. Thus we have it, oil obtained from the rocks, Petroleum was known to the ancients before Christ, but has only recently become so important. About a century ago, it was only used for burning in lamps. Today we use it to drive airplanes, motor-cars and railway trains.
In its crude state the oil is got from wells, sometimes near the surface and sometimes deep in the earth. Engineers bore deeply into earth, sometimes many hundreds of feet down.
It is a long and difficult operation to bore deep for oil. It is also attended with grave risks. When a fresh supply is tapped, the “gusher” or spring sometimes spouts suddenly to a height of several hundred feet. Thousands of gallons are thus wasted. Moreover, immense damage may be done to the surrounding district. Sometimes the attendant gas becomes ignited, and the flames may continue to burn for days are they can be put out. For these reasons, the men at work on new borings are usually dressed in leather suits and metal helmets. Their aim is to control the output by fixing steel caps over the borings.
As soon as the well is under complete control, the oil is drawn off into huge tanks of reservoirs. But it is not the clear, sparkling liquid we know so well. The crude petroleum is thick and dirty in appearance and must be refined before being placed on the market. Refineries were at first set up in the vicinity of the wells. As the number of wells increased, it was found more convenient to have large central refineries. These were connected, by means of pipes, with the storage tanks. Today, the refineries are usually erected either near the important ports of at some other point to which the country’s means of transit give easy access. It thus happens that many miles of pipe must be laid from each well to the refinery. In some cases the length of pipelines amounts to thousands of miles for a single area.
Crude petroleum is subjected to various processes at the refineries. One of the most important of the petroleum products is petrol. This is light and very inflammable oil or “spirit” used chiefly as the source of power in automobiles. Another important product of petroleum is a well-known illuminant called paraffin. Other useful products are benzine, paraffin wax, naphtha, vaseline or petroleum jelly, and various lubricating oils.