WHAT THE JOURNALS HAVE SAID:

"It is indisputably the most comprehensive and complete treatise on Petroleum, and this statement is true, no matter on what branch of the industry a test of its merits is made. It is the only book in existence which gives the oilman a clear and reliable outline of the growth and present-day condition of the entire petroleum world."-Petroleum World.

"A veritable encyclopædia of the Oil Industry ... even the comprehensive title fails to do full justice to the author."-Times Engineering Supplement.

"Will remain, as it has been in the past, the leading authority in the English language on the Petroleum Industry."-Oil and Colour Trades Review.

"A treatise which contains every conceivable item of information with regard to the subject. .. it should be of immense value to everyone to whom the Oil Industry is a matter of moment."-Syren and Shipping.

"An invaluable storehouse of information of every description relating to Petroleum."-Bulletin of the Imperial Institute.

"So perfect an example of what a book of reference should be."-Nature.

"The most important and complete single work on Oil ever published."-Oil News.

A TREATISE ON
ON PETROLEUM.

SECTION IX.

THE TESTING OF CRUDE PETROLEUM, PETROLEUM AND SHALE-OIL PRODUCTS, OZOKERITE AND ASPHALT.

A LARGE number of physical and chemical tests are applied to the raw materials and manufactured products to which this work relates. The industry is conducted upon a basis of recognised standards of quality, and testing is necessary on the one hand to satisfy the refiner that his processes are being properly conducted, and on the other to protect the buyer. Moreover, certain products are required to conform to statutory and municipal regulations, and prescribed tests have to be applied in connection with these restrictions.

Crude Petroleum.-The specific gravity of crude petroleum, and the amount of water and earthy matter in suspension, are usually ascertained. In many cases a test of fractional distillation is applied with a view of detecting any admixture of distilled products or residue. In Burma the flashing-point is frequently determined in connection with regulations relating to the transport. It may also be requisite, in the case of a crude oil from a new district, to take note of the colour and odour, to determine the flashing-point, the viscosity, whether separation of solid hydrocarbons takes place on cooling, and if so at what temperature, and whether sulphur is present, and if so in what proportion; also to ascertain experimentally what percentage of the usual commercial products, oil similar to the sample may be expected to yield on the manufacturing scale. In some instances it may be desirable to determine the elementary composition of an oil and its calorific value.

Petroleum Spirit and Shale Spirit. In the case of petroleum spirit or naphtha, including benzine, gasoline, etc., the specific gravity and range of boiling-points are the most important characters, but the fractional distillation test is also sometimes applied. The percentages of distillate yielded by a sample at specified temperatures are frequently determined in order that it may be ascertained whether the volatility is in accord with specified requirements. Petroleum spirit should leave no unpleasant odour when it is evaporated on the hand. Shale spirit is similarly tested.

Distillate (White Spirit). This product is now extensively used as a substitute for oil of turpentine in paints and varnishes, and, for such purposes, should contain no sulphur compounds. The range of distillation temperatures, specific gravity, flash-point, and colour are usually the most important physical characteristics of which data are required.

Kerosene and Paraffin Oil.-The colour, odour, flashing-point or fire-test, and specific gravity of kerosene and paraffin oil (from shale) are in most cases the only characters to be determined for contract purposes, and of these,

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usually only the flashing-point or fire-test is taken cognisance of in legal enactments. The oil is, however, occasionally examined as to its "burning quality," its "capillary power," its viscosity, its composition (as ascertained by fractional distillation), its acidity or alkalinity, its freedom from "soaps," its freedom from sulphur-compounds, and the amount of ash which it yields. Lighthouse Oil. The Trinity-House contract conditions for mineral oil intended for use in lighthouse lamps specify that—

1. The mineral oil required to be supplied under this contract is to be of the best possible quality, the greatest care is to be taken in its preparation, and it must be perfectly free from sulphuric acid.

2. In all cases, whether the oil be petroleum or paraffin, its flashing-point is to be determined by using the apparatus described in Schedule 1 of the Petroleum Act of 1879.

3. If the oil be petroleum, its flashing-point is to be not lower than 125° F. (close test), and it is to distil between 302° and 572° F., the temperature of the vapour, not that of the liquid, being taken.

4. If the oil be paraffin, its specific gravity is to be not less than 0.810, nor greater than 0.820, at 60° F.; its flashing-point is to be not lower than 140° F. (close test), and it is to distil between 302° and 572° F., the temperature of the vapour, not that of the liquid, being taken. 5. The illuminating power of the oil supplied, whether petroleum or paraffin, is to be equal to that of the best colza oil, when consumed in a TrinityHouse Argand lamp.

For the distillation test, about 250 grams of the oil may be taken, the operation being conducted in an ordinary distillation flask, with the bulb of the thermometer midway between the shoulder of the flask and the lateral tube leading to the condenser. The upper part of the flask should be wrapped in asbestos cloth.

The United States Fuel Administration, in Bulletin No. 2, incorporates the following specification for lighthouse oil supplied to the Bureau of Lighthouses

--

1. The mineral oil must have a flash-point of not less than 140° F. and fire-point of not less than 160° F. (Tagliabue closed tester).

2. The mineral oil must contain no free acids or mineral salts. Litmus paper immersed in it for five hours must remain unchanged.

3. One hundred grams of mineral oil shaken with 40 grams of sulphuric acid (specific gravity 1.73) must show little or no coloration.

4. When distilled from a still, so jacketed as not to allow of local heating, at a rate of not over 10 per cent. in ten minutes, the mineral oil shall not distil below 350° F. and 98 per cent. shall distil under 515° F. -the temperature taken being that of the condensing vapour.

5. When burned for 120 hours in a lens lantern, supplied with a fifth order oil lamp, the mineral oil must burn steadily and clearly without smoking, with minimum incrustation of wick, slight discoloration of chimney and less than 10 per cent. loss of candle power. Mineral Colza (or Sperm) Oil.-The colour, specific gravity, and flashingpoint of this oil are commonly ascertained.

Lubricating Oils. The principal characters to be determined in respect to lubricating oils are the viscosity, the flashing-point, the "cold-test," and the specific gravity. In some cases the loss by volatilisation on exposure to an elevated temperature is also ascertained. Lubricating oils should be free from acid and alkali. The viscosity of machinery-oils is usually determined in this country at the temperatures of 70° F. and 140° F., and of "cylinder" oils at

66

200° and 250° F. The extent of reduction in viscosity on an elevation of temperature is a point of practical importance; hence it is customary to make the test at two temperatues. The cold-test of "pale" machinery-oils is usually the point at which separation of solid hydrocarbons commences on a gradual reduction of temperature; and of "black" oils, the point at which the oil ceases to flow when slowly cooled. Compound" oil, or mixtures of mineral oils with fixed oils, are largely employed for lubricating purposes, and it is frequently necessary to determine the proportions in which these oils are present. Cylinder" oils-i.e. oils for the internal lubrication of steamengine cylinders-should not contain fixed oils (or at any rate not more than a very small percentage), as the latter are decomposed by high-pressure steam, and soaps are formed by the action of the liberated fatty acids upon the metallic surfaces. Black oils should be free from solid matter in suspension. Occasionally the chemist is called upon to determine whether resin oil is present, or whether any agent has been added to impart artificial viscosity. In Italy there is a differential duty on mineral oils, and a fractional-distillation test is applied to lubricating oils to determine whether more than the maximum of 10 per cent. of distillate is obtained below 310° C. The operation is conducted with 20 grams of the oil in an ordinary distillation flask, with the bulb of the thermometer just below the vapour-tube.

Paraffin. The testing of paraffin is usually confined to the determination of the "melting-point" (setting-point) and the percentage of oil, water, and dirt present.

Vaseline. The tests which are occasionally applied to this product are chemical rather than physical.

Petroleum Residuum. In testing petroleum residuum, it is usual to ascertain the specific gravity, the flashing-point, and the freedom from water and coke, or other solid matter.

Fuel Oil.-Oil for use as fuel should be free from solid matter in suspension, and is usually required to have a specified minimum flash-point, to retain its fluidity at a low temperature, and to contain not more than a specified percentage of water and of sulphur compounds. Suitable tests for ascertaining whether the oil conforms to contract requirements in these respects are accordingly applied.

Gas Oil.-Oil for gas-making is usually purchased on the basis of a specification which prescribes the method of testing.

Crude Shale-Oil.-In the testing of crude shale-oil, it is often sufficient to make a fractional distillation of a portion, and determine the specific gravity of each fraction of 5 per cent. and the setting-point of the less volatile.

Ozokerite. The commercial analysis of crude ozokerite has for its object the determination of the percentage of refined ozokerite which the sample is capable of yielding.

Asphalt. The examination of asphalt is usually confined to the determination of its physical characters at different temperatures, and its solubility in carbon bisulphide or other solvent.

The various tests to which reference has been made in these introductory remarks, and certain chemical tests, will be found fully described in the following pages.

At the Petroleum Conference held at Baku in 1886, the undermentioned classification of Russian petroleum products was adopted :

1. Benzine-two sorts, viz. :

(a) Light benzine-colourless; used for manufacturing indiarubber goods, and distilled at a temperature not below 130° C. or 266° F.

(b) Heavy benzine-of a pale yellowish colour, yielding 10 per cent. refuse when distilled at a temperature as high as 150° C. or 302° F.

2. Kerosene-specific gravity 0-830; two sorts:

(a) Safe-flashing-point not less than 25° C. or 77° F.

(b) Unsafe-flashing-point below 25° C. or 77° F.

3. Astralin-specific gravity 0-850; of a pale yellowish colour; flashingpoint not less than 50° C. or 122° F.

4. Solar oil-specific gravity above 0.850, but not exceeding 0-880; flashing-point not below 80° C. or 176° F.; may be of very pale yellowish colour.

5. Lubricating oils-specific gravity from 0-880 and upwards.

6. Crude oil-specific gravity from 0-850 to 0-880; flashing-point below 70° C. or 158° F.

7. Masut, or crude oil deprived of volatile light substances by exposure to air-specific gravity above 0.880; flashing-point above 70° C. or 158° F. and residue, locally called ostatki, flashing-point not below 140° C. or 284° F.

8. The different petroleum products in a solid state-asphalt, ozokerite, etc. 9. Ceresine, paraffin, vaseline.

10. The different greases, varnishes, and mastics derived from petroleum.

CRUDE PETROLEUM.

Ordinary crude petroleum is required, in the United States, to conform to the following rule of the New York Produce Exchange, except as regards specific gravity, the rule having been relaxed in that particular in consequence of much of the crude petroleum now obtained having a greater density than 43° B. :"Crude petroleum shall be understood to be pure natural oil, neither steamed nor treated, free from water, sediment, or any adulteration, of the gravity of 43° to 48° B." (0.809 to 0.786 specific gravity).

In order to determine whether the petroleum is a pure natural oil," a sample is subjected to fractional distillation, each fraction being one-tenth of the crude oil by volume, and the densities of the several distillates are determined. The following results, obtained in the examination of two typical samples, indicate the form of the certificate handed to the buyer :

Oil from Parker District. Gravity 46° Baumé. | Oil from Bradford District. Gravity 43° Baumé.

1st product,
2nd

57° B.

3rd

53° B.

4th

49° B.

5th

46° B.

6th

42° B.

7th

41° B.

8th

42° B.

71° B.

60° B.

54° B.

49° B.

45° B.

41° B.

40° B.

41° B.

42° B.

The regular gradation in the densities of the fractions exhibited in the foregoing certificates is regarded as a satisfactory indication that the oil is a natural product.

The natural lubricating oils (crude petroleums) of Pennsylvania, Ohio, West Virginia, and Kentucky have been classified by the West Virginia Transportation Company according to density, and subjected to the following test :

"In receiving and making delivery of oils shipped by the company, the water and sediment contained therein shall be determined by mixing an