VOL. 5, NO. 7
RELATION OR
CHEMISTRY TO PETROLEUM INDUSTRY
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THE RELATION OF CHEMISTRY TO THE DEVELOPMENT OF THE PETROLEUM INDUSTRY IN THE UNITED STATES* JOHN LEWIS MOILLIET, BAYLOR UN~VERSITY, WACO,TEXAS There are very few industries in which chemistry plays a more vital part than the petroleum industry; yet up to a few years ago very little was known of the chemistry involved in the production and refining of petroleum. In the past few years, and particularly with the advent of the alltomobile industry, there has been a greater interest in petroleum chemistry. The importance of cracking processes is well known, but there are applications of chemistry to petroleum that have and will have increasing importance to the indus~ try as i t becomes even more complex. There are such applications from the time drilling begins until the finished products leave the refinery, and it is the purpose of this paper to make a general survey of the relation of chemistry to the development of t h e petroleum industry, rather than to dwell a t any great length on refinery technology. In oil field exploration the most important contribution in recent years has been the carbon ratio theory of David White, the geologist, who made the discovery that in areas where b o t h coal a n d petroleum occur, the frequency of occurrence of oil is inversely proportional to the carbon ratio of the coal. This theory has already proved of some value in oil field exploration, but the future should bring out many more applications of geochemistry to oil field exploration. In the earlier oil wells, as in the refineries, the processes were comparatively simple, and there was no need for chemical experts. As the industry has become more complex, however, there have arisen problems that have been solved, or are being solved, only by the help of chemistry. One of the most serious of these problems has been that of water entering wells through faulty casings and either forming emulsions, which are
* Prize-winning college essay,
1927-28.
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JOURNAL OB CHEMICAI, EDUCATION
Tau. 1928
broken up at considerable cost, or else so diluting the oil as to render the wells no longer profitable. Methods were early developed for cementing casings a t places where water flowed in, but the difficulty lay in the fact that the source of the water could not always be found. Consequently, a method developed by which analyses were made of samplesof water from different levels as the well went down, and water that came in later was recognized by its chemical constitution. Ordinary expression of its composition by means of grains per gallon, etc., have been replaced in many cases by the method of interpretation used by Chase Palmer, which is briefly as follows. Instead of expressing the analyses in the ordinary way, they are expressed in terms of the different radicals or ions present, and by dividing the weight of each radical present by its equivalent combining weight, the reaction capacity is found. I n terms of reaction capacity the relative alkalinity or salinity of the water is expressed. This method enables more minute expression, while the general characteristics of the water a t diierent levels can be expressed more generally. Another development in the solution of problems arising from water, in which the chemist plays a part, is the tracing of the flow from well to well of underground water. By this means the iormation of strata can be studied and data collected to help on water problems. The use of dyes, pumped in a t one well, has been of considerable value, but lately a method bas been developed in which salts of rare metals, such as lithium, are pumped down and then recognized in the mineral residues of samples collected a t neighboring wells by their flame tests. Even more important than the above uses has been the application of chemistry in making substitutes for the methods of cementing out water in leaky casings. The first substitute was drilling mud, which was made of the dirt from the well itself, and requiredno chemistry in its preparation. There are, however, many wells in porous soil that drain away drilling muds, while a t the same time gas disturbances prevent the setting of cement. The chemist saved the situation in this instance with hydraulic lime, which is used in the same general way as concrete. A typical hydraulic lime has the following composition by weight: 10.5170 silicon dioxide (sand), 12.4070 ferric and aluminum oxides, 39.241, calcium hydroxide (slaked lime), 20.G170 magnesium hydroxide, 1.G570 sulfur trioxide, and 6.17v0 carbon dioxide. While concrete is still used in large amounts, hydraulic lime is being used more and more on wells that could not be saved by the other method. The last application of chemistry in crude petroleum production has been in the problem of handling emulsions of oil and water. It is absolutely necessary t o break up these emulsions before the oil is piped for any great distance, in order to prevent corrosion of pipe lines, and physical means are expensive. Consequently, the production of crude oil has been greatly
increased by the chemical treatment of emulsions. Compounds have been developed which break them up by softening the water present and by weakening the surface tension of the oil. This branch of petroleum chemistry is still in its infancy, but the results already obtained indicate that work on better emulsion-breakers should bear fruit. The present goal for such investigators is the development of an oil-soluble compound, which would be more economical, would require less agitation, and could be more universally applied. This is a problem that comes under colloid chemistry, and its solution will depend largely upon the attention that the colloid chemist brings to bear upon it. After the oil has been freed of water, it is ready for refining, an essentially chemical process. Refining was formerly merely a process of fractional distillation which could be done by untrained men, but the greater number of products now required, together with the development of cracking processes, has made chemical research and the application of chemical engineering more and more important. The first important contributions of chemistry to petroleum refining were Frasch's method of desulfuretting oil by means of cupric oxide, and the all-important cracking processes. The cracking of heavy oils to yield the lighter hydrocarbons is too familiar a story to be given in much detail here; it is sufficient to say that heating the heavier members of the groups a t high temperature and pressure will break them up into the lighter, more volatile ones. The cause of this development of cracking processes has been the rapid rise of the automobile industry, and this same industry has developed a new problem for chemistry, that of fuels that will give a greater mileage and that will not cause knocks in the motor. With the rise of aviation, it is safe to predict that there will be a demand for even more efficient fuels. There have already been several additions to our knowledge of cracking, and one of the more recent discoveries, and one of the most promising, has been that of catalytic treatment of cracked distillates in the vapor phase. Cracked distillates, like the vast majority of petroleum products, must be purified with sulfuric acid and sodium hydroxide in order to remove the color present, which is due to the presence of unsaturated hydrocarbons. It has been found that if these vapors be passed through fuller's earth which is kept a t the same temperature as the issuing vapors, the earth catalyzes the union of the unsaturated compounds into heavier ones with higher boiling points, which causes them to condense. The other vapors pass off to the regular condensers. While the practicability of this treatment of distillates has still to be tested more completely, i t should a t least suggest lines of approach to the solution of the problem of cheaper treatment of distillation products. There are several instances in both the refinety and oil field where &em-
istry has been applied in the development of the petroleum industry. A problem that is of importance to practically every industrial process of any size is that of pure water for boilers. In petroleum refining there is constant use of steam distillation, and a t the well the machinery is operated by steam; so chemical methods of purifying water are very necessary. Scales in boilers reduce the heat conductivity of the metal and thus increase expense, and clog up boilers and steam pipes, often causing explosions. By a knowledge of simple inorganic chemistry, the harmful salts can be removed by adding salts that contain radicals that will precipitate the harmful radicals. This has proved of great value, though there are cases where recourse has to be made finally to distillation of the water. Perhaps the greatest hazard that the oil refiner and producer must face is that of fire. This is increased by the fact that most of the oil products, besides being highly inflammable, are lighter than water and hence cannot be extinguished by ordinary methods. This danger created a demand for a substitute for water in fighting oil fires. The chemist's answer was "Foamite." As in the ordinary fire extinguisher, carbon dioxide is generated, though in this case it is by the action between sodium bicarbonate and alum. To this mixture is added some substance, such as licorice, which causes the bubbles of carbon dioxide to have thick skins and cling to any surface on which they are poured. The thick foam of water, licorice, and carbon dioxide floats on top of the burning mass and quickly blankets out the flame. The last application of chemistry to the development of the petroleum industry has been its relation to the development of the branch industries, the shale oil and gas industries. So closely is the shale oil industry related to the petroleum industry, and so closely do they resemble one another, that the shale oil industry can be considered a branch of the larger petroleum industry. For many years oil has been produced in Scotland from oil shales, and there are deposits in the United States that are far richer than those in Scotland, though up to the present they have not been developed. The Scottish industry came near collapsing when cheaper oil began to be produced in the United States and Russia, but the value of the ammoniamade as a by-product saved the situation. Had it not been for the chemical value of ammonium compounds, the industry could not have survived. American shale yields a high percentage of ammonia, and i t may be safely predicted that a t some time in the future there will be a development of this important national resource, in which the chemist will play an important r81e. The oil from shale comes as a result of the destructive distillation of the semi-solid kerogen which breaks up into products closely resembling the products of petroleum refining. A more detailed study of the reactions involved should lead to dis-
coveries that will make this branch of the petroleum industry substantially established. In a sense a by-product industry of petroleum, the production of natural gas, is very closely related to petroleum production and is closely bound up in its development. Already natural gas is becoming of importance in more ways than as a fuel, due chiefly to chemical investigations. It has been discovered that the crude natural gas often contains many vapors that can be condensed and refined as lighter fractions of petroleum. It has also been found that many natural gases in the Middle West and Southwest contain helium in large enough amounts to make extraction worthwhile. Non-inflammable gases are in great demand for airships, particularly in wartime; so chemists of the Bureau of Mines and the University of Kansas, working on the suggestion of the isolator of helium, Sir William Ramsay, have devised methods of extraction. Plants for extraction have already been erected a t Fort Worth, Texas. The gas is put under heavy pressure and allowed to escape through a small opening, as in the making of liquid air, with the result that all the gas except the helium liquefies. Thelatter is collected and storedfor use. Other methods have also been developed, but the essential principle is the same. It can be seen from the above brief sketch that both in the history of the petroleum industry and the history of the petroleum itself chemistry has played, and does play, an important part. Nevertheless, it is easy to see that this relationship must become even more pronounced in the future. In every single instance that has been cited above, the applications of chemistry are still in the early stages, and the value of the science is therefore largely a future value. If the chemist meets this challenge as he has met the problems that have been solved, and we have every reason to believe that he will, the problems and mysteries of the petroleum industry should soon take their places with the problems that have already been solved by chemical ingenuity and research. REFERENCES 1. 2. 3. 4. 5.
6. 7. 8. 9. 10.
U. S. Bureau of Mines Bullelin 210. U. S. Bureau of Mines Bulletin 195. U. S. Bureau of Mines Bullelin 163. U. S. Geological Survey Bulletin 479. U . S. Geological Survey Bullelin 653. U. S. Geological Survey B d k t i n 729. Ind. Eng. Chem., 1923,pp. 888-90. Ind. Eng. Chem., 1924,pp.185-9,8903. Ind. Eng. Chem., 1925,pp. 108S89, 103b5. Chemkal end Metalluraicd Encineerinc, Feb. 1 , 1919, PP. 104-14.
13. Bacon and Hamor, "The American Petroleum Industry." 14. Benson, "Industrial Chemistry." 15 Hop.?, "Chemistry in Industry."
