Petroleum

Petroleum (rock-oil, from Lat. petra, 'rock,' and oleum, 'oil'), an inflammable liquid, essentially composed of carbon and hydrogen, which exudes from the earth in various parts of the world.

Copyright 1891 in U.S. by J. B. Lippincott Company.

(1) General History.—It is impossible to state when petroleum was first discovered. In some form it seems to have been applied to the uses of mankind in the earliest periods known to history. The ruins of Nineveh and Babylon indicate that the asphaltic mortar used for their walls and buildings was made from a partially evaporated petroleum, obtained, doubtless, from the springs of Is, on the Euphrates. This is probably the 'slime' of the Old Testament Scriptures (Gen. xi. 3). Herodotus (i. 119; iv. 195), 500 B.C., writes of the springs in the island of Zante, 'I have myself seen pitch drawn out of a lake and from water in Zacynthus,' &c. Strabo (xvi. 2) refers to the bitumen found in the valley of Judea, and sold to the Egyptians for embalming.

Diodorus describes the same product obtained from a lake in Sicily and sold for the same uses. Pliny, Plutarch, Aristotle, and Josephus mention the deposit in Albania on the Adriatic Sea. The holy fires of Baku on the Caspian Sea, worshipped for ages by the people dwelling near, and the goal of pilgrimages even from India (see Vigne's Travels in Cashmir and Little Tibet), have been sustained by apparently inexhaustible petroleum stores. The North American Indians collected what was known as Seneca Oil from petroleum springs, and the indications are that long before them the Mound Builders, who worked the copper-mines of Lake Superior, the lead-mines of Kentucky, and the mica-mines of North Carolina, not only gathered the oil coming from natural springs that appeared on streams, but even dug numerous wells in Pennsylvania, Ohio, and Canada, and dipped up the oil that flowed into them. Trees now growing in the earth thrown out in digging the wells, or in the wells themselves, show that the work was done from 500 to 1000 years ago.

(2) Growth of the American Industry.—But the growth of the American industry, which has given the world what can be fairly termed the people's light, has been within the last half of the 19th century. From 1850 to 1858 many experiments were made with petroleum, both in the line of collecting the crude article and of refining it when secured, but with indifferent success. Among the promoters of these efforts was the Pennsylvania Rock-oil Company, incorporated in 1854 under the laws of the state of New York. The superintendent of this company, E. L. Drake, in 1858 started to sink a well in one of the old pits supposed to be of prehistoric origin, near Titusville on Oil Creek, Venango county, Pennsylvania. Water and quicksand choking this open well, he decided to drive an iron pipe from the surface of the ground down to the solid rock. On August 28, 1859, after going to a depth of 34 feet, he found that oil rose nearly to the top of his pipe at the surface of the ground. He had 'struck oil!' In the general excitement that followed this successful venture wells were sunk in great numbers along Oil Creek, French Creek, and the Alleghany River. Adventurers and investors flocked thither from all parts of the country. What was soon known as the 'oil region' was transformed from an almost unbroken forest into camps and towns in which fortunes were made in a day, and often as quickly squandered. Many wells yielded nothing; others lasted but a short time, while some gave enormous quantities of oil. But the producing fields were, and are still, constantly changing; new ones being discovered, old ones failing. For example, Pithole City, near Titusville, Pennsylvania, in 1865 next to Philadelphia the largest post-office in Pennsylvania, has now entirely disappeared, and the site of the city become a farm. Crude petroleum is at present secured in many parts of the state of Pennsylvania. Special mention might be made of McKean, Warren, Elk, Forrest, Erie, Crawford, Venango, Clarion, Butler, Washington, and Greene counties. It is also produced in some parts of other states—New York, Ohio, West Virginia, Indiana, Colorado, Wyoming, Kentucky, California, and Texas. Traces of petroleum are found also in many other of the United States.

Between 1890 and 1897 the product of petroleum in the United States doubled, the production in 1897 being 60,568,081 barrels, of a value of 40,929,611; while the export of mineral oils had a value of over 56,125,000. In the same year the United Kingdom imported 185,665,376 gallons, valued at £3,335,271. The use of petroleum for fuel, as in motor-cars (see GAS-ENGINE) has of late greatly extended.

The accompanying table gives the production of crude oil in the United States, the stocks, and the prices realised at the wells for each year, 1861 to 1890 inclusive. The unit of measurement of crude oil is a barrel of 42 gallons.

There are no reliable statistics showing the number of producing wells in existence. It is estimated by those best informed on the subject that in what is known as the Pennsylvania fields there were in 1891 between 30,000 and 40,000. At first the wells were of no great depth, extending down to what was termed the first sand. Afterwards wells were sunk to the second and third sands. The average depth is from 1600 to 1800 feet, the shallowest wells being about 500 feet, the deepest about 3000 feet. Many wells, particularly when first completed, are flowing wells; that is, the oil is forced up through the tube composing the well, and reaches the surface of the ground without pumping. This of course indicates that the oil in the reservoir below the surface of the ground is held under pressure; but as an outlet is given for the oil the pressure subsides, and it becomes necessary to lift the oil by pumps. There are to-day a few flowing wells in America, but practically all the wells are pumped. Crude petroleum as it comes from the ground varies in general appearance from a bright lemon colour to a greenish black, all the intervening shades being found, and in gravity (weight or density) from 38 of Baumé's scale to 50, all the intermediate gravities being secured. The same well will, at different stages of its life, give oil of different colours and gravities, the colour growing darker and the gravity heavier as the well grows older. In 1862 it was found that in many cases dry wells could be made to resume their yield, and declining wells to continue production by being shocked with torpedoes. In 1897-98 a commission took evidence in England as to whether petroleum with a flash-point as low as 73° (Abel close test) is dangerous, and reported by a majority that a flash-point at 100° should be taken as the standard of safety. And see EXPLOSIVES.

One of the most interesting features of the growth of the petroleum industry is found in the devices for transportation. The oil was at first carted in barrels over rough roads to the point of consumption or of loading into railroad cars. The wooden barrel gave place to light iron tanks on wheels, and the ordinary freight car for oil in barrels to wooden tank-cars, and these in turn to iron tank-cars, some of which are of 8000 gallons capacity. But the greatest advance was made when pipe lines for the transportation of petroleum were introduced. Samuel Van Syckle, of Titusville, Pennsylvania, put down the first successful line, extending from Pithole to Miller's Farm, a distance of four miles. The oil region is now a network of pipes. They carry oil from the wells to central points for storage or for delivery to the trunk lines to be pumped to the refineries. Powerful pumps move the oil rapidly in vast quantities for great distances. There are twelve to fifteen trunk lines of 6- and 8-inch pipe, carrying the oil from the point of production to the refineries handling it. The most important lines are known as the National Transit Line, South-west Lines, Macksville Line, Tidewater Line, Western and Atlantic Line. By these crude oil is delivered at New York, Philadelphia, Baltimore, Cleveland, Buffalo, and Chicago. The total length of these main lines and their several branches and feeders is fully 25,000 miles. The American trade in petroleum is largely controlled by the Standard Oil Company.

(3) Distillation and Products secured by Distillation.—The main product of petroleum is refined oil for illuminating purposes. To secure this the crude petroleum is subjected to heat in stills of different sizes and shapes. In most cases the still used is a horizontal cylinder, made of iron or steel plates $\backslash frac\{1\}\{4\}$ to $\backslash frac\{3\}\{8\}$ inch thick, resting upon, and partly surrounded by, brickwork, as in the case of ordinary cylindrical boilers. A large outlet or vapour-escape pipe carries the vapours over into a long condensing pipe or worm immersed in a vessel containing water constantly supplied to cool and condense the vapours passing through the condenser coil. The first products of distillation are the light gaseous fluids which can be condensed only at very low temperatures, and then kept in liquid form only under pressure. Generally this is not attempted. Then follow in order the various naphtha and refined oil products, until the residuum left in the still represents from 6 to 10 per cent. of the original charge. The yields of the various products varies according to the grade of crude charged in the still, and also somewhat according to the amounts of the different products which the manufacturer finds it most desirable to make. From the different Pennsylvania oils the range of products is as follows: Naphthas, 8 to 20 per cent.; refined oils, 78 to 70 per cent.; residuum, 9 to 5 per cent.; loss, about 5 per cent. From the naphtha many special products are made—gasolenes for lighting, stovonaphtha for cooking, gas-naphtha for gas-making. The refined oil distillates, as they come from the still, are impregnated with tarry matter and inflammable gases, imparting a greenish colour and an offensive odour. To remove the gases the distillate is heated in a still worked entirely by steam. To remove the colour and improve the odour the distillate is then transferred to a large vertical cylinder with a conical bottom, called an agitator, where, by means of an air-blast, the oil is thoroughly agitated with sulphuric acid, resulting in precipitation of much of the objectionable impurities with the refuse acid. The shape of the agitator admits of this refuse being drawn off to go to the acid-restoring factories or to fertiliser works. The distillate is then washed with soda or some other alkali, to neutralise any trace of acid, and with water.

From the residuum left in the still several grades of heavy oils and paraffin-wax are obtained by further distillation in other stills. The oils are used for lubricating purposes, the wax is used for candles. The limits of this article will not admit of even passing mention of the many other by-products secured in the way of lubricating oils, greases, wax, &c. It is safe to say that two hundred different kinds of products are secured from crude petroleum.

While the sale of petroleum products in America is very large, the exports largely exceed the home consumption. The figures below, which show the petroleum exported from the United States in the fiscal years ending June 30, are taken from reports of the Statistical Bureau of the United States Treasury Department at Washington. It will be noted that the total exports for the twenty-seven years 1864-90 have amounted to $1,043,474,435. A larger percentage of the mineral-oil product of the country is exported than of any other product, except cotton.

(4) Petroleum in other Countries than the United States.—There are oil-fields other than those in the United States producing petroleum in commercial quantities—those of Baku, Burma, Canada, Galicia, Peru, Japan, and, last to be developed, of Langkat, or Lankhat, in Sumatra.

The Baku (q.v.) field yields immense quantities of crude of heavy gravity, which on being distilled gives only a small percentage (25 to 32) of burning oil of satisfactory quality. However, as the crude is very cheap, and the balance of the product from distillation can be sold for fuel, the refiners of the Russian crude have been able to compete with other refiners for a share of the world's trade in petroleum. The petroleum of Canada, like that of several fields in the United States, particularly in the state of Ohio, is of low gravity, 26 to 42 Beaumé, and has a peculiar acrid and nauseous smell, on account of the sulphur it contains. It is difficult to refine, but its production has been fostered, and it supplies a large demand throughout the British provinces. The Japan field has been known for many centuries, but the cheapness of the American refined products renders it impracticable for products from the Japan crude to compete. Production has been completely checked.

(5) Origin of Petroleum.—This topic is treated here somewhat out of its natural order, not because it is lacking in interest, but because so little seems to be known about the chemical geology of petroleum. There have been three leading theories advanced, under some one of which all of the results from different lines of investigation can be classed: (1) Petroleum is a distillate produced by natural causes; (2) petroleum is indigenous to the rocks in which it is found; (3) petroleum is a product of chemical action. A full summary of the results of the investigations under each one of these theories is given by Professor S. F. Peckham in his report as special agent of the United States census for 1880. He inclines to the belief that Pennsylvania petroleum is of vegetable origin and the result of distillation.

See B. Silliman, jun., Report on Rock-oil or Petroleum (1855); J. S. Newberry, Rock-oils of Ohio (1859); T. S. Hunt, History of Petroleum or Rock-oil (1861; Report Smithsonian Institute); A. Norman Tate, Petroleum and its Products (1863), and Examination of Petroleum, &c. (1869); Draper and Pease, 'History of Petroleum,'

Scientific American (vol. xii. 1865); A. Gesner, Coal, Petroleum, and other Oils (1865); S. S. Hayes, Petroleum (1866; 39th Congress, Ex. Doc. 51); T. Sterry Hunt, Geology of Petroleum (1866; Geological Survey of Canada); Cone and Jones, Petrolia, a Brief History of the Pennsylvania Region (1870); C. F. Chandler, Report on the Quality of Kerosene Oils (1870); Report from the Select Committee of the House of Lords on the Petroleum Bill (1872); A. N. Leet, Petroleum Distillation (1884); B. W. Crew, Petroleum; and books on petroleum, its manufacture and uses, by Brannt (1895), Boverton-Redwood (1896), R. N. Boyd (1896), and Jaccard (Paris, 1896). See also the articles FUEL, GAS, GAS-ENGINE, NAPHTHA.