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they arise and will not only bring about the use of widely distributed and now practically valueless low-grade or smoky coals, but will recover the by-products. Rrooks estimates that each ton of bituminous coal may yield from 20 to 30 gallons of crude oil, 2.5 gallons of crude motor spirits, 10 pounds of ammonium sulfate, 3000 to 4000 cubic feet of gas or 800 to 1OOOB. t. u., and 1500 pounds of coke, and asserts that the by-products from the half billion tons of bituminous coal now wastefully burned would, if recovered, have a value greater than the most productive coal mine in the country. Meaning of L‘Super-Power” and “Giant Power”
Vol. 18, No. 10
which have been set up in a more or less haphazard manner. Giant power may be compared to the planning and building of a transcontinental railway, constructed with reference to the largest and best needs of all of the people, while superpower is more nearly comparable to the linking together of small existing railroad systems, each built originally to meet some immediate need and with little reference to the economics of a large comprehensive system. In advocating the principles of giant power the thought has been to plan in advance a large and comprehensive power system which will utilize the natural resources in the coals and their by-products, and also bring in the water powers, looking ahead to the ultimate need of the people, and with first consideration of the widest possible service to the homes and farms, as well as to industry.
The terms super-power or giant power have been used more or less interchangeably. There is, however, a radical difference in their significance. In super-power we have Conclusion the conception of joining together, a t their boundaries, The ultimate vision in all of this is that of the correlation several individual “principalities” or domains in which each electric corporation is supreme in its monopoly of of all of these chemical and mechanical operations in hanpower transmission and sale. This joining together is dling our fuel resources in cooperation with a better control for the purpose of greater efficiency and increased profits. of our waters-with necessary solution of political obstaclesIt should result in lower costs to the consumers, but it all leading to the cheapening of the cost of electric power. does not necessarily change or improve the local individual This must naturally be followed by its wider use in the faccharacteristics. Giant power, on the contrary, contemplates tories, in transportation, and particularly in the homes the development and adoption of a well-considered plan of the people, providing them with tireless servants, lightenand the organization of a wide territory regardless of the ing their drudgery and adding to their comfort and prospersonal peculiarities of these individual ‘Lprincipalities” perity.
Trends in Power Development with Special Reference to Mineral Fuels’” By A. C. Fieldner’ PITTSBURGH EXPERIMENT STATION, BUREAU OF MINES,PITTSBURGH, PA.
RESENT-DAY trends in power development are most manifest in two directions : (1) centralization of power production with distant transmission and great subdivision in use by municipalities, railways, industrial establishments, and for other needs of the community; and (2) great subdivision of power production by small, light internal combustion engines generally using liquid fuels. The small steam-power plant a t factories, except where exhaust steam is required for heating or processing purposes, is being replaced by electric motors operating on purchased power, and the internal combustion engine has replaced the horse almost completely for vehicular power. The small gasoline engine has become standard equipment for farm-lighting and power purposes, and has permitted a tremendous development of automotive transportation that has exercised a profound economic influence in the United States.
P
Great Subdivision of Power Is Outstanding Trend
The outstanding feature of the present trend is the great subdivision of power. Whether obtained from an electrical transmission system or from liquid fuel, power may be
* Presented at the Round Table Conference on “The Role of Chemistry in the World’s Future Affairs” a t the Sixth Session of the Institute of Politics, Williamstown, Mass., August 3, 1926. * Published with the approval of the Director, U. S. Bureau of Mines. 8 Chief chemist, U.S. Bureau of Mines, and superintendent, Pittsburgh Experiment Station.
had conveniently, cheaply, and in flexible form for almost any purpose and in units as small as desired. This subdivision of power is destined to produce further profound economic effects. It may even cause a return in some degree to the small home industries that prevailed before Watt’s engine brought about the present factory system. For example, the electric refrigerator is now displacing the large central ice plant in furnishing cleaner and more convenient cooling service in the individual home. Electrical laundry appliances permit practically all of the power conveniences of the large central laundry to be applied in the home. Electrical power may be had not only within the reach of the distributing lines of the great central station, but also a t remote country places through the use of the liquid-fuel engine in small direct-connected electric current generating plants which require almost no attention while in operation. The common use of the gasoline engine for automotive transportation and miscellaneous power purposes, combined with the distribution of electrical power from large central stations, has made it unnecessary for industries to cluster around the source of power. European industries never were centralized to the extent that took place in the United States. Now, however, a definite trend toward the scattering of industrial plants in smaller cities and even villages has started in the United States. This decentralizing trend should promote more healthful and enjoyable working and living conditions than are possible in the large congested city.
INDUSTRIAL A N D ENGINEERING CHEMISTRY
October, 1926
Figure 1 4 from Ely and Rittman’s paper on “Prosperity and Power” shows the trend in Pennsylvania of industry moving away from congested centers. Influence of Power Development on National Prosperity
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carrying on investigations on the conservation and beneficiation of mineral fuels. The widespread interest in fuels and combustion is evident from a glance a t the enormous increase in the literature on this subject. Some fifty important books have appeared within the last seven years on coal chemistry, high- and lowtemperature carbonization, fuel engineering and combustion, to say nothing of articles in the current technical press. There have also appeared in the same period the following periodicals devoted entirely to fuels--Fuel i n Science and Practice in England; Chaleur et Industrie in France; Brennstoff-Chemie in Germany; and Fuels and Furnaces, Combustion, and Coal in America. Recently, there has been formed an Institute of Fuel Technology in England and a special oFganization of - Fuel and Combustion Engineers is being talked of in America. It is evident that the trend toward scientific and c h e m i c a l control of combustion and power development i s v e r y strong and that we are on the threshold of a period d u r i n g w h i c h the efficient utilization of mineral fuels will be greatly increased. Let us review briefly the principal presentday trends in this direction.
The developments in power production made possible by a wealth of liquid and solid mineral fuel resources, combined with ingenious application of power to the ordinary manual operations of home and industrial life, are perhaps the prime factors in the material prosperity of the United States. They have in effect so increased the productiveness of human labor that wages beyond all imagination of the last century are paid for a given number of hours of work. thus affording leisure for the laborer to better the living conditions of cis family and in fact to indulge in the luxuries of the rich of former years. The bettering of general living standards has in turn provided r e m u n e r a t i v e employment for the multitude of workers r e l e a s e d by the in- 2 ‘2 creased and more effi- 2t 2 cient use of p o w e r , Y t h u s e l e v a t i n g t h e if: plane of material pros- 4 z perity of the people as a whole. Although the United States has led in this great develop0 Communities of less than Cities rnth population C l h e of 10,oOO to ment due to the enor10,ooOpopulation 5O.ooO population over 5O.ooO mous supplies of easily Figure 1-The Trend of Power in Pennsylvania. All Manufacturing Industries, Fuel Losses in Small Power Plants won coal and petroIncluding Iron and Steel leum, t h e trend in C o m b u s t i o n is the other countries is in the same direction. Sir Robert Peel most important of all chemical reactions. Life itself could stated one hundred years ago that the future belonged t o not exist without the burning of carbon in the human body; the nation which could produce the most coal. At the a large part of the earth would be uninhabitable without present time it seems that he should have said “gasoline” heat from combustion of fuels to warm our homes; and instead of coal, although we must admit that ultimately modern civilization is dependent wholly on the energy and his prophecy stands, since the present flood of petroleum power derived from combustion reactions. is a temporary episode in the world’s history. I n the next I n the ordinary boiler plant of a small factory the effihundred years it will be the nation which makes the best ciency of furnace and boiler is seldom more than 50 to 60 use of its coal that will be most prosperous and will assume per cent, which means that in many cases one-half or more the industrial leadership of the world. of the heat of the coal is lost by heat in chimney gases, unburned fuel in the refuse, and in radiation losses. The Importance of Scientific Research in Conservation and high fuel consumption of the small power plants, together Efficient Utilization of Fuel Resources with the high cost of labor and attendance of small units, The application of scientific research, and especially and the time lost in repairs and in firing up the furnace, has chemistry, is the means whereby the less favored nations led to the substitution of purchased power in small and even as regards mineral fuel resources can hold their positions large industrial establishments in such cases where the examong the leading industrial group. The World War haust steam cannot be utilized for heating or processing forced upon every nation a realization of the tremendous purposes. While this trend toward centralization of power generation importance of fuels in their various forms. It demonstrated the value of scientific research and the need of each nation in large units is now in full swing, it is evident that whento provide adequate sources of those particular forms of fuel ever an industry needs process steam or steam for heating that were best adapted to modern warfare-namely, petro- purposes it can more profitably generate its own power, leum and its products. It stimulated much research along a t least where power is a by-product of the low-pressure lines which did not promise commercial returns under steam required for other purposes. Considerable thought ordinary conditions, but which promised means of obtaining is now being given to this problem, and an improvement the necessary forms of fuel when the nations were thrown of efficiency in this direction is to be expected. entirely upon their domestic resources. Every important country, from the United States with 117,000,000 people, Increase in Thermal Efficiency of Central Power Stations to New Zealand with 1,300,000 people, has established, The progress in fuel economy of the large central station either directly or indirectly, fuel research laboratories for has been tremendous. The increase in over-all thermal 6 Sci. M o n f h l y , 10, 639 (1925). efficiency of engine, boiler, and furnace in the last three
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years has been greater than in any like period since the days of James Watt. In 1913 the most efficient central electric stations produced a horsepower hour from 11/* pounds of coal. Today the best record is a horsepower hour from 3/4 pound of coal-a net saving in fuel of 40 per cent. Compare this consumption of 3/4 pound of coal with the 3 to 4 pounds of coal consumed for each horsepower generated by a small factory power plant. National fuel economy demands the elimination of many small plants, and the smoke nuisance which they create. The modern mechanical stoker and pulverized coal combustion combined with automatic combustion control apparatus provide practically perfect combustion, so that one seldom observes anything more than the faintest wisp of smoke from the stack of a super-power station. The immense boilers of the Crawford Avenue Station of the Commonwealth Edison Company of Chicago each evaporates 300,000 to 400,000 pounds of water per hour. The steam is generated a t 550 pounds pressure and superheated t o 725" F. before entering the turbines. The aggregate capacity of four turbine units is 235,000 kilowatts or over 300,000 horsepower. Present plans for the ultimate plant call for 750,000 kilowatts, or 1 million horsepower. Electrical power is generated with a thermal efficiency of 27.4 per cent, a figure beyond the imagination of the previous generation. However, this figure will be surpassed in the future. Two Scottish engineers, Dr. Mellanby and Dr. Kerr, conclude from both theoretical and practical analyses of the use of high-pressure steam generation, made possible by the development of heat-resisting alloy steels, that the remarkable over-all thermal efficiency of 35 per cent is possible. This means a horsepower from half a pound of coal. W. L. R. Emmett, of the General Electric Company, has successfully obtained this high degree of efficiency by using mercury and steam in an experimental power plant a t Hartford, Conn. It is not withn the scope of this paper to go into the technical details of how fuel economy is being increased by continual improvements in stoker and furnace design, by powdered coal combustion, by utiliz-ng the waste heat of flue gases for preheating air and water, and by the use of higher temperatures and pressures. However, it is des red to call attent on to the outstanding fact that centralization of power development in larger units has made these economies possible and practicable Political agencies all over the world now recognize the economic importance of power and are fostering wherever possible further progress In this direction. According to Samuel I n ~ u l l ,president ~ of the Commonwealth Edison Company, the power requirements of the United States are today a little more than one-half supplied electrically, 38 million horsepower being supplied electrically and 31 million nonelectrically. The nonelectrical power is distributed as follows: manufacturing plants, 13 million horsepower; mines and quarries, 4 million; farms 14 million -gasoLne automotive engines are not included. Electric power companies are conducting an aggressive campaign for this remaining 47 per cent of installed nonelectrical power, and they are making rapid progress in bringing t h s power to the central station, all of which results in a saving of coal and cheaper power. The Role of C h e m i s t r y in Power Development
Although chemistry has taken an important part n bringing the niodern power station to its present high efficiency, it is destined to play a much larger part in future developments. l h e r e is beginning an unmistakable trend toward 6
Elec. World, 87, 1120 (1926).
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the combination of gas and electric generation in a single plant with the recovery of by-products in addition. We may look forward, with considerable confidence, to a future by-product power station analogous to the by-product coke plant of the present day. Experimentation is going on in both Europe and America on the pretreatment of coal by low-temperature carbonization in conjunction with the boiler furnace of the power station. By bhis process gas, motor fuel, tar, and fuel oil are to be extracted from the coal before it is burned under the boiler. Pound for pound these by-products are more valuable than the raw coal, and they will be needed in the comparatively near future to augment the waning supply of petroleum, which our tremendously developed automotive industry requires. Such processing of power-plant fuel is of particular importance to nations which have no domestic sources of petroleum. The outstanding importance of liquid fuels in modern warfare places the recovery of oil from coal as one of the first items in a program for the national defense. The Royal Commission on the Coal Industry of Great Britain in their recent report6 discusses at some length the question--"What improvement can be effected in the present methods of using coal for the production of power, light, and heat and of recovering by-products, with a view to insure the greatest possible economy in production and the most advantageous use of the coal substances?" They point out that ample quantities of motor fuel and petroleum substitutes, as well as ammonia for fertilizer, would be obtained if all the coal for power and heating purposes were first processed to recover the by-products. The commission states further' that: If it be found possible t o devise processes technically sound and economically profitable for the pretreatment of coal, so as t o produce a solid smokeless fuel which is not inferior, or is little superior in heating efficiency t o the raw coal, then, (1) T h e atmosphere of t h e towns and industrial districts could be made smokeless. The saving on the present cost in labor, money and cleanliness, would be great. The effect upon the health of the people, upon their temperament and outlook, upon the arts of architecture and sculpture, and the amenities of the towns generally could not fail t o be large, and wholly beneficial. The nation would obtain from its own soil a considerable supply of oil for use in internal combustion engines and other purposes for which natural oils are now imported. This would offer a measure of security against t h e possibility t h a t the world's supply of natural oil may fall short of the demand, with a consequent excessive rise in price. I t would render this country t o a large extent independent of imported oil supplies for the Navy, Army, and Air Force.
The heads of the large American public utilities are beginning to appreciate the trend toward the processing of coal, as witnessed by Mr. h u l l ' s recent Atlantic City address a t the meeting of the National Electric Light Asso~ i a t i o n . ~He said: Expansion of the electrical, the gas, the coke, and the steel industries should go hand in hand t o realize the best economic conditions and the conservation of fuel and energy. It may not be out of place t o draw attention to another subject which our electricity supply companies and our friends in the gas business might well pay close attention to-namely, low-temperatwe carbonization of fuel. It is well worth our while t o spend money on research in this field To those who may be fortunate enough t o solve the problem in this field the reward will be great. T h a t the solution will be found in a comparatively few years, I have no doubt, It seems to me safe to predict t h a t ere long electric supply companies will produce electrical energy and gas, to say nothing of valuable by-products under the same roof, from one plant, and from using one class of fuel. 6
Report of Royal Commission on the Coal Industry, Vol. 1, p. 18 H. M. Stationery Office, London. Loc. c i t . , p. 26.
(1926). 7
October, 1926
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Pretreatment of Power Plant Coal and the Motor-Fuel Problem Some 10 billion gallons of gasoline will probably be used during 1926 in the United States alone. While this requirement is being met a t the present time by the rich petroleum resources of the country, this continually increasing demand cannot be met for many years. We must ultimately turn to coal to supply the need of liquid fuel and the day is relatively near when petroleum substitutes from coal must necessarily come into use. Low-temperature carbonization of the coal consumed by power plants is the logical second step to follow the present motor benzol fuel from by-product coke ovens now blended with petroleum gasoline in some localities. Assuming an average yield of 3 gallons of light oil suitable for motor fuel and 25 gallons of tar oils for each ton of coal consumed in power plants, the average yield from the present annual coal consumption of 60 million tons of central station power plants in the United States would be 180 million gallons of light oil and 1500 million gallons of tar oils. The light oil after suitable refining can be blended with gasoline for motor fuel and the tar oil can be used either completely or in part for fuel oil or oil for Diesel engines. Even with the utmost possible development in centralized power stations, the total quantity of these liquid fuels will be a small percentage only of the total liquid fuel requirement, so that an unlimited market will be available. It is granted that the market price for such fuel by-products is too low to yield a profit under present competitive conditions with petroleum, but the inevitable diminution of flush production is bound to result in an increasing market price which will make this byproduct recovery a t the power plant a profitable enterprise. In addition there must be considered also the by-product of 3000 to 5000 cubic feet of high-quality gas that may be obtained from each ton of coal. Therefore, the complete by-product utilization of coal in future power production means a combination of gas and electric public utilities which will so process the coal to extract needed fuels of higher form value-gases and liquidsfrom the coal before burning the solid residue in the steamgenerating plant. The gas will be distributed for heating purposes and the liquid fuels will serve to augment the petroleum resources for internal combustion engine fuels. It is true that such cornbination of gas and electricity generation is difficult to work out on account of dissimilar load factors. The first solution will probably apply only to base-load plants. Nevertheless, this trend of processing coal is world-wide, although industrial, political, and geographical considerations with reference to petroleum and coal resources will force developments sooner in some countries than in others. The world’s petroleum resources are probably less than 5 per cent of the coal resources, and the demand for liquid fuels by the growing use of automotive and small internal combustion engines will necessitate the ultimate use of the coal resources for petroleum substitutes. Fuels for Automotive Engines Parallel with the trend in the centralization of power production in great electric stations has been the extraordinary growth in numbers of automobiles, particularly in the United States. The development of the internal combustion engine as a simple and reliable power-generating apparatus, the wealth of cheap petroleum, and the resourcefulness of the chemist in transforming petroleum into suitable gasoline fuel have combined to produce this tremendous development in production of automotive power. The domestic consumption of gasoline in the United States, of which the motor car uses about 80 per cent, amount-
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ed to 7.5 billion gallons in 1923 and to 10 billion gallons in 1925, an increase of 331/3 per cent in two years. The total number of automotive engines for 1926 is estimated a t 21 million, an increase of 38 per cent in two years. Chemistry has played a most important role in the improvement of cracking and refining processes to increase the yield of gasoline from crude oil. The newer cracking processes not only permit the transformation of any kind of crude oil-paraffin, naphthene, or asphaltic base-into motor gasoline to any desired degree of completeness, but also provide motor fuels that may be subjected to higher compression in engines of more efficient design, thus giving a materially greater mileage per gallon of gasoline consumed. Intensive chemical and physical research on combustion in the engine cylinder has resulted in the discovery of compounds which when added to gasoline suppress the undesirable “detonation” or “knock” that results in loss of power and smoothness of operation. Tetraethyl lead, the most effective of these knock suppressors, permits the use of highcompression engines that give some 50 per cent greater mileage than the ordinary gasoline engine. The present intensive research in the laboratories of the petroleum refineries and of the automotive industry will lead to much more efficient fuels and engine design so that the future motor will consume half the gasoline per mile that is required today. Thus increased efficiency in the utilization of petroleum will go hand in hand with the processing of coal in the centralized production of electric power and smokeless domestic fuel, to maintain our present high stage of automotive transportation under conditions of declining petroleum production. The ultimate goal is the processing of all coal into smokeless form-solid, liquid, or gaseous-with all power centrally generated and distributed electrically except where not feasible, as for automotive purposes, or where exhaust steam is used for heating or processing. This ultimate goal means a clean atmosphere in our cities, the opportunity of living in less congested districts, ready access of the city dweller to the country for healthful recreation; urban advantages on the farm, and a general increase in the productiveness of every one. One can scarcely vision the profound influence in many directions of the present trends in power development. The nations that are richly endowed with mineral fuel resources have an inherent advantage in taking a commanding lead in the material prosperity of the world, but certainly the application of scientific research can do much to alleviate the handicap of those who are less fortunately endowed with natural resources.
Cocoa By-products as Fertilizer Materials Until the last few years the only cocoa by-product in America cheap enough to interest the fertilizer industry was the shells, with such related waste material as cocoa dust and sweepings. As a result of the enormous demand for cocoa butter, however, two additional by-products of importance, the cocoa press cake and solvent-extracted cocoa, are being produced in large quantities. They are ohtainable a t prices which have made them available for use as fertilizer materials. Utilization of cocoa by-products as fertilizer materials, says the Department of Agriculture, is in competition with their use as feedstuffs and as sources of theobromine alkaloid and caffeine. Until recently about one-fourth of the by-product cake produced was eventually consumed as fertilizer. Ground cocoa cake has been reported by manufacturers t o be satisfactory as a “rough ammoniate” filler and conditioner in mixed fertilizers. For use as fertilizer material average press cake might be expected t o bring 80 per cent as much per ton as the solvent-extracted cocoa. An ideal system for the utilization of by-product cocoa cake would provide for: (1) recovery of the f a t ; (2) recovery of the alkaloids; and ( 3 ) retention of the valuable food and fertilizer constituents in the defatted, dealkaloidized residue.
