t
I&EC Lecture Series
I I
I
C. C. FURNAS
University of Suffalo, Buffalo 21, N. Y. When the ACS Division of lndurhiol and Engineering Chemistry orked Clifford C. Furnar lo present the &ond IaEC Feolure Leclura, they picked not only an occomplirhed scientist but one with two other coveted r i r t u e c a b i i i l y to speak and abilily lo write. Dr. Pumas is (I forceful and interesting speaker, and he writes for both technical and popularized xience iOurndL Of most interest i n ~ooneclionwith his ledwe, however, is his deep concern for the future of civilirotion in all ih Orpech. Because of this interest he has wrinen "The Ned Hundred Years." "Man, Bread, and Destiny," "America's Tomorrow." and "The Storehouse of Ciriliiotion." W e feel that his statementi and interpretations ~onceming our energy Y)U~COI and needs con be accepted with confidence. underrtmding that much of the material mud be (I prodwt of iudgmemt rother thon fad. Just 0 few months ago Dr. Furnos become Chancellor of the University of Buffalo. Although he came to this position from (in eight-year tenwe as director of the Cornell Aeronautical Laboratory. education is not new to him. He taught (or eleven years ofler receiving his doctorate i n chemical engineering from the Univerrily of Michigan. Five years with the Bureau of Mines ond four years os director of research for Curtis-Wright complete his experience log.
2446
II I
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Energy
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Sources
of the Future
I N D U S T R I A L A N D B N G I N k E n i N G CHEMISTRY
46, No. 12
~~~
l&EC LECTURE SERIES-Future
M
AN'S early urge to use 8ources of energy other tban those of his own body probably arose from his inherent lazinesswhy work 80 hard? So he enslaved the more tractable animals. His inventiveness, whetted by bis initial succes8, was then turned to inanimate form-wind and falling water-and he found that their employment not only made life eaaier, it also made it better. He further found it desirable to burn fuel to keep himself comfortable in winter and to use combustible materials for chemical processes, such as extractive metallurgy. By the time the steam engine waa developed, civilization's appetite for energy was an accepted fact, and the industrial revolution was readily spawned. Civilization now literally depends on a copious and continuing supply of energy. It is generally believed that the eventual peace of the world rest8 substantially ou the equitable distribution and maintenance of supplies of good8 and services from industry for the benefit of all men. Industry requiw power and, until a point of saturation is approached, indutrial benefits are about proportional to the m o u n t of inanimate energy being used. We appear to be far from that point of saturation. Most persons are interested in at least the next small increment of civilization aa they expect to be part of it. It is therefore quite realistic to query: what of the future? A good question, but it is not an easy one to answer. The principal virtue of an answer may he that it will stimulate others to reach more valid conclusions. The approach of this study and its exposition eaeily falls into the timehonored framework of attack on a complex research problem: 1. State the roblem
2. Analyze d e problem 3. Solve the problem by aocomplisbing discrete and speciiio task8
3 S?
with effic
? ?lop a feasible pn version o clear energy into rgy?
>f storing
I we find improvec' irisal energy product nuclear means?
Deoemher 1954
--L
INLu
D 1
nI m
L A 11 Y
The problem, aa I see it, is that for many pa& of the world there is not enough energy of the right kind available a t ' the right place a t the right time and that in the foreseeablefuture this maladjustment may spread to all the populations of the world. There are some who look a t the gross data of energy consumption and tbe availahle supply and contend that there is noproblem-at leaat not for us or for our grandchildren many times removed. I feel certain that this conclusion is unduly restrictive as to geography or time, or both. And even for the more favored parts of the world, such aa the United States, there in a problem worthy of the attention of the best scientificand engineering brains. Problems of Energy Sources and Use Belong to the Whole World
My own analysis of the problem hinges largely on data presented h a recent hook by Putnam (8). This publication in primarily pointed toward the most plausible future role of nuclear energy but it is also, in my opinion, the most complete summation of pertinent information on the whole problem of energy and its use that haa been compiled to date. Its hundreds of references make it by far the most effective 8ource book available. The problem of future energy supplies is of such scope and complexity that it mnnot be visualimd or realistically handled except on a world basis. A time apan of one century is also redistic for a discussion of this subject because if s major problem develops during that time, its solution may depend on work that should he started now. In this analysis certain reasonable assumptions are made: First, there will continue to be a movement of all the pwples of the world toward induatrialiaation and away from mere subsistence agriculture. This movement will probably intensify. Secondly, to satisfy needs, energy in variOU8 forma must be available at reasonable cost. The world industrial economy might be able to withstand a doubling of the preaent real cost of energy, but it could hardly operate with severalfold increases. Thirdly, if, in future years, the rea1 cost of large blocks of energy should go down rather than up, new use8 will develop and greatly increase demands over those indicated by current developments. The following trends Beem important in the analysis of the problem:
1. The entire world ia in a period of unprecedented upswing in population. The present population stands at 2.4 billion. The most probable estimate for a century hence is 6 to 8 billions. A very dramatic, immediate, and completely unexpected reversal in the rate of increase would be required to change the probable figure by m y significant amount. 2. The U. S. population, now somewhat over 150,000,000, is growing at the rate of over 17 per thousand per year, three times the rate of mid-1930's and nearly twice the present growth rate of the world population. Even if this growth rate slides to aero by the year 2050 (an almost inconceivable trend of events) our population a century hence will approximate 375,000,000. 3. As populations become more concentrated, they cannot be supported in the essentials of life by old-style subsistence agriculture. They must lean more toward industry, which requires more energy. Hence, increasing concentrations of populations call for an increasing energy supply per capita. Thus world energy demands increase more rapidly than does population. 4. During the past century the rate of increase of world energy utiliaation (output) has averaged about 2.2% per year, compounded. The world figure now bas reached 3%. During this same century the rate of increase of energy utilization in the United States averaged 5.4% per yeer, compounded. Recorded suatained average rates of increase over recent decades for Japan, the United States, the U.S.S.R., and Germany have been 3.2, 3.4, 3.9, and 4.4% per year, respectively. 5. The total energy requirement (input) of a system is determined by the energy actually ueed (output) and the e5ciency of utilization. The estimated aggregate efficiency of the energy
nswe found, aid
conv y be achim
Energy Sources
fi I"
u I NE ERIN 0 CHE M I S TRY
2447
INEERINO, DESIGN, AND PROCESS DEVELOPMENT
1 Figure 1.
~ p y s t e mof
World Population increase and Probable Energy Demands during Next 100 Years
the United States haa trebled since 1900 and now stands
at about 30%. The correspoudlng figure for the world is 22%. 6. In the &t eighteen and a half centuries since the birth of Christ the total bum-up (input) of energy for the world amounted
to between I3 and 9 X 10" B.t.u., equivalent to a rate Of about 0.004 X 10" B.t.u. per year. During the century 185s1950 the total input was about 4 X B.t.u. BY 1850 the input about 0.01 x 10" B.t.u. Per Y-. The Present rate of rate input is about 0.1 X 10" B t.u per yem, a tenfold increase in 100 years. 7. The rate of input into the total u. 8.energy system Was about 0.003 X 10" B.t.u. per year in 1850 and 0.036 X 10" B.t.u. per year in 1950, a twelvefold increase in a century The U. S. input rate is now about 37% of the world total. 8. Although a great deal of energy is stored in the earth's -st in the form of foasil fuels, particularly coal, only a small proportion appeara to be economically recoverable. The total energy in fd fuels (coal, oil, pas) recwerable at no more than twice 1950 coats is estimated to be, for the world, 27 X 10" B.t.u.; for the United Statee the estimate is 4 X 10' B.t.u. Although these data indicate that the United Statea may have
2448
enough economically recoverable fossil energy to last anomer century, a more detailed analysis of the trends of recovery indic a w that we may mu into serious partialdepletion difficultine within the next two to three decadea. g. The two major, largely untapped sowcee of enme nuclear materids (uranium and thorium) and sunlight. Eoonomically recoverable world resources of uranium and thorium are presently estimated to be 25,000,000 tons and 1,000,000 tom, resPectjvely. A ~ ~breeding - ~ a net & d i v e burnllp of one third of the mined metal, these would yield an energy input of 575 x 10" B.t.u. Some 3200 x 10" B.t.u. of solar energy reaches the earth's surface per yea1-32,OOO times the present rata of input into the world energy system. This datum on solar energy is based on I321/.% transmidon through the atmosphere.
Population Trends Are Slow Moving but Irrerirtibie Campared to previous eraa in human existence the rate of increase in the world's population is now practically explosive.
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 46, No. 12
I&EC LECTURE SERIES-Fukre Energy Sources
100
90
80 70 60
4d
50
8
c
40
30 20
10 1800 20 40
60 80 1900 20 40
60 80 2000 20 40 60
YEAR Figure 2.
U. S. Projection to Year 2050 of Relative Proportions of Three Components of the Energy System-Work, Process Heat, and Comfort Heat
T h e complete list of causes is obscure hut undoubtedly improved medical science, effective means of transportation, improved agricultural methods, the gradual replacement of subsistence farming by industry, and the rising spirit of nationalism are contributory. It is unlikely that actual ignorance of methods of birth control has been a major factor. In the long trend, major, death-dealing world catastrophes such as the Black Death and two world ware appear to have had but minor effects. In each instance the results have been evident for a few years only, then the populstion marches inexorably on. It is obvious that the present exponentid increase (with a relatively large exponent) cannot go on for many centuries. If it did, the entire earth's surface would become a solid mass of quivering human flesh. Eventually there will come eome controlling and restraining influences, even though at the moment we cannot visualiee them in detail. We can he fairly certain, however, that when the people of the world become fully aware of and truly frightened at the inevitable hazards of serious overpopulation, birth control will become peculiarly effective, and world population will stabilize a t some workable figure. That papulation figure cannot he predicted hut it will undoubtedly he much greater than that visualized by Malthus, because the modern combination of industry and scientific agriculture can support much greater population densities than he could have anticipated. Conaideratian of this several-centuries-offpopulation problem may be postponable, but the present-century trend can no longer he ignored whether we consider food, clothing, education, roads, automobiles, or energy resources. Like the crest of a river flood, population trends are slow-moving hut, in any given cycle, practically irresistible. The pressures already in motion will have their effect a hundred years from now, and there is little we can do about them. As already indicated, by 2050 A n . world population will increase by a t least three fold. It may be somewhat more than that. It will hardly be much less. December 1954
Some contend that already half the world is half-starved by American standards and that the Malthusian specter of starve tion will soon begin to be effective. Through the literal starve tion of millions or billions of people the upward trend will be reversed. But this merely expresses the philosophy that when there is no room in the barrel, there is no room in the barrel. This might have been a valid concept in pagt centuries, hut it happens that this barrel is now made of flexible f a b r i e t h e warp is nationalism (or race pride), and the woof is modern technical and scientific knowledge. With the fund of scientific and technical knowledge the world now has, it will he physically possible to feed, clothe, and house at le& 6 to 8 billion people on this planet and between 300,000,000 and 400,OOO,000 within the present boundaries of the United Statee. We can argue endlessly about sociological and political desirability of this situation hut, while we deliberate, the net world population steadily goes upward at the rate of over 70,000 more persons per day. We had best accept the idea and prepare for it. Energy Demands Rise with Increased Industrialization In BO far as past experience is me-gful, the record of the United States irr typical of the impact of full-fledged indnstrial-
Table l.
a
Comparison of Population and Energy-Use Trends
(Period, 1850-1850) Av. Annual Increase. % p e a r , Comwunded Total Per capita POPUlapower power tion 0"tP"t ovtput World 0.60 2.2 2.0 United Stataa 1.82' 5.4 2.1 Rate substantially sfhotad by immigration.
INDUSTRIAL AND ENGINEERING CHEMISTRY
ENGINEERING, DESIGN, AND PROCESS DEVELOPMENT Sea Water Processing Can Become Great N e w Energy Consumer
The foregoing discussion is b d on extrapolation of past experience. Suppose some major new factors are added t o the pattern of energy needs, what will happen to the forccast? Now that the industrial pattern includes automobiles, airplanes, air-conditioning equipment, and numberless other manufactured devices, what great new energy consumers can there be? I will suggest only two:
Solar Still Recovers Fresh Water from Sea Water
ization on energy demands. This provides some idea of the \vorld trend for the next century, since the ~ o r l seems d bent on following the industrial pattern which has been effectively nurtured here. As pointed out, increased population requires increased industrialization, and this requires increased per capita utilization of energy (Table I). The per capita increase in energy output in the United States in the century 1850 to 1950 was from 10 X 106 to 73 X 100 B.t.u. per year per person, an increase of 7.5-fold. If t,his U. S. experience of per capita rate of increase proves to be a,pplicablc to the world pattern for the nest century and if the population increases threefold, then by 2050 - 4 . ~ the . annual world need for energy output will have increased by some 2250% (221/~-fold). This is merely an automatic estimate arrived a t in the niannci’ of a statistician, by twiddling with figures. Let us approach it from another angle. At the present time the United States has about of the world’s population and produces about 50% of the world’s industrial goods and services. It also produces (or utilizes) about 3770 of the world’s input of cnergy. However, its average utilization efficiency is about 30% compared to the world average of 22%. Hence the U. S. proportion of the world’s output of energy is 37 X a0/22 or about SO%, a figure that matches its proportion of industrial production. Simple arithmetic shows that if the other 14//15 of the world were brought up to the (the United St,ates), the total world’s level of the highest energy output would be immediately increased by 750%. If the whole world, then, achieves the present per capita level of industrial production and if the expected threefold increase in world population occurs in the next century, the energy output demand will increase by 2250%, even without any increase in the present U. S. annual per capita need. The matching of this figure with the first extrapolation has no particular significance; it does, however, afford a rough check. As I see it the extrapolated demand figure is on the low side. It implies that during the course of the coming century the world average level of industrialization will reach only that of the United States in 1954. Whereas with properly distributed energy supplies at reasonable prices, lyorld industrial progress and hence energy demand should grow substantially. 2450
1. Recovery or fresh water from aea water: The best nietliod~ suggested thus far are not within the order of magnitude that is feasible for large scale uses, such as irrigation. But as population and hence pressure for food increases, the economic urge for a practicable process will become much stronger, and the laws ol physics will probably be stretched t,o their utmost to supply the physical need. Past gun battles over the v-atei holes of o i ~ r western plains and the current international conflict over the use of the River Jordan are merely minor illust,rationa of thc’ bitterness of contention aroused by inadequate water supplies. 2. Recovery of large amounts of many essential material;; f z m sea water by methods analogous to those presently used for the rather limited recovery of bromine and magnesium: As our extravagant use of mineral wealth continues and population increases, the depletion of resources will become crucial. The sca is an almost liniitless reservoir of many essential elements ill minute concentrations. It will not be overlooked as a continuing storehouse of the niaterials of civilization. Perhaps extensive use of base-exchange reactions will be t,he key to success here. Also, as the years advance and depletion creeps upon us, eyes and new processes may well be pointed toward the extraction of mineral wealth from land deposits of much lower concentrations than are now considered usable.
Any practical processes devised for these recoveries will almost inevitably be large consumers of energy; they could overshadow any individual use8 known today. Thus a prime prerequisite of eventual n.orld peace appears to be ail even more bount~iful supply of energy than we now visualize, available almost everywhere a t low cost. Efficiency of Utilization Remains Below 50%
Efficiency, as used here, means the ratio of energy output, in the form desired for use, to total energy input. In t,he Cnited States this efficiency ratio for the aggregate energy system has risen threefold since 1900-from 10 to 30%. The viorld-wide average is currently 22%. Can these ratios be substantially and permanently raised and thus ease the demand for energy input? FIere the laws of physics are on the discouraging side. It is true that heat used for providing comfort or for the process industries might be used a t a high efficiency (90% or more). Rut a large and increasing proportion of our energy supply is utilized to perform mechanical work, largely based on the use of heat engines. Here the second law of thermodynamics raises its unwelcome head and restricts us to practical efficiencies which are, on the average, well below 50%. Unless some unforeseen physical discoveries are made to circumvent the heat, engine and, hence, this unfortunate situation, we are doomed to live from now on with average efficiencies of utilization on the low side of 50%. Gndoubtedly as time goes on some improvements will be made; it, is not unreasonable to assume that ovcr the next century rorld-wide efficiency may increase from the present 227, to 30 or 35%. This may have :in alleviating effect, but, it is certainly no panacea. Facts and Trends Set Up a n Order-of-Magnitude Estimate for Year 2 0 5 0
Using these trends and facts, an estimate can be made of the world energy demands a century hence. The answer obtained by any one person will probably depend to a substantial degree on
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 46, No. 12
MEC LECTURE SERIES-Future his current level of fatigue m d t>heimmediate status of his digestive processes, ae well :is on the figures at hand. However, if any credence is given the data presented here, he must come to the conclusion that the world’s bona. fide energy demands in 3054 A D . will be at least t,enfold greater than they are in 1954 :tnd conceivably 100-fold greater. This increase range of one t,o two orders of magnitude iu a practical one for our consideration. To meet the demanda of the lower figure with our present state of scientific and technological knowledge will be difficult, indeed. To meet the top figure will be impossible unless something new is added. This is the problem facing us, our children, and our grandchildren. The limitations of mere quantity of energy available, however, do not completely circumscribe the problem. Other factors coniplicate the matter, Most impelling of these is the geographical distribution of sources. Icffective transportation systems partially alleviate problems of maldistribution, but they never eliminate them. Political factors as well as economics and engineering are involved. The recent A4nglo-Iranianbout with Premier Mossadegh and the Mexican appropriation of American oil properties some years ago indicate that international relations are always close at hand to add to the ferment. UnM the brotherhood of man is strengthened beyond any foreseeable status, it is well to consider the virtues of controlling essential energy supplies. This adds a t h c t i o n t o the idea of exploring sources not now utilized. E v m total quantity and geographical and political distribution do not adequately fix t,he frame of reference of the energy problem. Almost as important as any other factor is the sort of package in which t,he energy comes. The demand for type of package is determined largely by the use to which it is put. The pattern of use has changed very rapidly over the past century. lvailable data (Figure 2) indicntP t,hc changes of a century in the U. S. pattern. The end use has a major impact on the sources that are utilized. The effect of the xutomobile on the demand for work is iiiost pronounced. And the automobile, a t least as now utilized, cxlls for liquid fuel. This and such other factors as availability, cleanliness, economics, and convenience have markedly changed the pattern of sources of input energy.
Table
II.
Energy Sources
Distribution of Use of Energy Sources in the United States Use,
Energy from
1850
76 1960
Gas
Oil Coal ( d l kinds) Wood Hydroelectric
Table I1 shows the changes in sources of energy in the United States over the past century. Although for some end uses, there can be considerable flexibility in selection of source, other parts of the pattern are fairly rigid: Stationary power plants can interchange coal, oil, and gas with relative ease; houses can be heated with electricity if the cost is low enough; the factory operator cares not whether hi& electricity comes from a hydroelectric plant or a coal-fired steam plant; but coal-fired automobiles will never be popular as long as present combustion processes are used; and a liquid fuel would appear t o br a “must” for most aircraft of the foreseeable future. Hence the form of the energy package must match the end use with a reasonable degree of practicality, and this is a substantial factor in the ultimate solution of the energy problem. It calls for some major technological tricks. Foreseeable Energy D e m a n d s Suggest Changing Source Patterns
Solutions to the energy supply problem will be found not in one but in several directions. KO pattern of solutions will remain constant; it will shift with changes in needs, rpsources, end uses, and state of the art. However, the possible energy sources for use in the foreseeable future can readily be listed: 1. Solar energy 2 . S u c l ~ a energy r 3. Fossil fuels 4. Water power 5. &liscellaneous
Leaf Filters, Loaded with Magnesium Hydroxide, Are an Important Part of Dow‘s “Magnesium from Sea Water’ Operations at Freeport, Tex.
December 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
2 31
ENGINEERING, DESIGN, AND PROCESS DEVELOPMENT Table Ill. Foctors to Apply to Previous Estimate of U. S. Cool Reserves Available at Substantially Present Costs To eorrect for 1909 overeathate of erriatenoe To CDrreot for upgrading required 8eaiii thickn-. 14 ta 24 inches 3. To aomot for coal that will he left in the ground 4. To wrreot for high wh c o d 5. To correct for 50% loss in mnuertinp low wade aosils to usable form Composita faotar 1.
2.
0.50 0.50
0.M) 0.95
0.m 0.m9
opinion that these miscellaneous sources will not, in toto, rise
to great importance in the future.
Water Power Provides about 1% of Present Energy Input of World Before exploring these problems in detail, the possibilities and limitations of each, in reverse order of the listing, are delineated: 5. Misceheons. The listing under miscellaneous is, to a considerable degree, arbitrary. Putnam ( 8 )haa considered most possible items and evaluated their potentinlities. His data, adapted for this presentation, are given in Table 111. These are only rough estimates despite the use of three decimal places. The small numbers emphasize the relative magnitude of the possible contribution. Sin& present inpuh into the world energy system, as reported here, is about 10 X 101% B.t.u. per year, these miscellaneous 8ourOes cannot he regarded aa insignificant. They can be of suhshntial importance for an iuterim period, particularly in special locations and for particular purposes. These data, however, represent &bout the maximum amonnta that could be economically utilized. The
4. Water Power. Water power constitutes roughly 1% of the energy input of the United S t a b and of the world. Not only is it convenient and often inexpensive, it frequently serves 88 an aid and economic justification for Bood eontrol and navietion. Though bydroeleotric power will probably always he utilized, it will not solve the world's energy problems. The total world hydroelectric potential is estimated at roughly tenfold the present installed capacity. Even if this is'eventually fully exploited, the percentage contribution to the total e n e m supply will remain small in view of rapidly increaeing world demand, AB a matter of sentiment, I hope that the potential is bever completely harnessed. Though a large dam may be beautiful and useful, it is certainly mthetically and sociologically desirable to have some natural water c o r n . In general, water power seems to be approaching B point of stable msturity. It has no major research and development problems of ita o m . It will follow a regular and orderly growth curve--emall in solving the total problem but continnously important in many locations. 3. Fossil Fuels. Since twentieth century civilization relim to a preponderant degree on the burning of fossil fuela, it is desirabla
I
- 1 ?
sieeoftheres~o~willnotgrowwithtime. I n view of the forthcoming rapid rise in world energy demands (at least tenfold in the next century), the potential of theee miscellaneous sources will soon begin to lose signi6cance by default. Even if fully exploited in the acceptable coat structure, they $odd aupply only about 2% of the needs's century hence, without regard to geographical maldistribution. Further, considerable idvention and a great deal of business promotion would he required to realize the full posaibilities. Some of this will probably be forthcoming, but it is my 2452
18w20
40
60
8019002040
60
802ooo
YEAR '
Figure 3.
Percentage Ccritribution to the Energy System from Each Maior Source-1 800-1949
INDUSTRIAL AND ENGINEERING CHEMlSTRY
Vol. 46, No. 12
l&EC LECTURE SERIES-Future Enegy Sources to explore thie area in a fair amount of detail. How large are the reserves of coal, oil, and gas? How much can we d o r d to pay for them? Economic factors make a ditlerence in the answer to the first question. Putbases his analysis an real recovery coats of no greater than twice 1950 6gures and thus arrives at an answer to the second question. It is an arbitrary answer, certainly, but it makes a good deal of economic Reuse and serves as a baais for a realistic evaluation. One school of thought contends that no great consideration need he given to price, a t least not for a long time to come. If fuel is wanted, people will pay for it. If they prefer food to gasoline, they will walk. However, we are not faced with a protm of convenience or comfort or simple wants, we are rapidly ing confronted with a n unprecedented sociological force that primarily a composite of papulation pressure, nationalistic and cia1 fervor, and a maas desire for technologieal advancement. ese forces can only be countered with an effeotiveworld-wide dustrial pattern. A readily available economic energy supply not be a convenience, it will be a necessity ranking with -as essential as food and a prime requisite of food produoNations have fought for food and they will 6ght for energy. tern of energy scarcity cannot in the future he an adequate ation for a stable civilization. A continuing unstable world e hydrogen bomb era is not plettaqt to contemplate. For a generation the authoritative estimates of world coal r e ves were those determined a t the meeting of the Geologicsl gresa in Toronto in 1913 which concluded that the heat conof the global coal reserve was 180 X 10" B.t.u.; of this, 90 X 18 B.t.u. was credited to the United States. Toronto was 8 nerous with its neighbors, however. In 1909 Campbell ( 1 ) estimated the United States Peserve at 3.1 trillion tons, nivalent ta about 66 X 10" B.t.u., and this figure was accepted this country until 1939 when Hendricks (e) made a new stic estimate of 3.2 trillion tons, equivalent to some 67 X
World War 11, however, several other American experts k a critical look at the matter, injecting practical economic ctors into their consideratiom. They adjusted previous timates by the factors shown in T d e IV.
0
Peak production of oilmay be reached between 1955 and 1960.
0
Peak production of all United States coal may be reached before 1990.
If w e are to avoid the risk of seriously increased real unit costs of energy in the United States, then new l o w cost sources should be ready to pick up the load by 1975 or sooner.
availsble. Reopenin the argument with more experta rmght reveal evidence that t%eestimates are unduly pessimistic. There might also he a percentage change upward, but there will not be a change in order of magnitude. In trying to face our future problems realiatically, it is probable that the pessimistic approach is the sound one. Both the United States and the U.S.S.R. have experimented with underground gasilicntion of thin s e m and low grade coals, with rather indifferent 8uccess. The belief that such a process would make it possible to recover the energy from some of the very large deposita that cannot be mined at reasonable costa. Low calorific value producer gas can be and has been produced in this manner, but the costs have not been low and widespread utilization would he di5cult. The indication is that this is inherently not much more than an interesting experiment, although the process might be practical in certain locations under special eircmtancea. The arguments on the extant of economically recoverable reserves of oil and gas are roughly analogous to those for coal.
Estimates of Heat Content in Oil and Gas Reserves (Becoversble at eo nore t b n 1 .a times 1850 cmts)
able IV.
Heat Content. B.t.u. X IOU Estd. undis aovemd reaewee reenwen Total 0.25 0.25 0.5 Proved
United States World
O.O@
4.06
5.0
Thus the factor to be applied to the previous figure, when viewed though economic glasses, appears to be about 10%. It is disturbing suddenly to lose 90% of one's inheritance, but if that is the situation, the m n e r it is realized the better. In addition to this loss, we have burned up about 0.8 X 10" B.t.u. of our blue ribbon reaerve since 1909, and this figure must be suhtracted from the credit side. Further, the United States preference (or necessity) for liquid fuel is an important factor. With any present known processes it takes over 200 B.t.u. of coal to make 100 B.t.u. of liquid fuel. When it becomes necessary to utilize coal to Satisfy the motor car demand for liquid fuel, the economically available energy will be approximately halved again. Using these data Putnam concludes that the net energy avaiiahle from U. 8. reserves of coal (at no higher than twice 1950 costa) after adjustment for IOSS in synthesis is 3.1 X 10' B.t.u. Aoolvina these criteria to the world situation. the enme author eonrludcs that the feasible figure for the world reserve is 21.0 X IO' B.t.u. Althoulrh these data reoreseat a substantial amount of enerw. it is o n l y a small fraction of what we used to think would%;
.. .
December 1994
~
Humble Oil and ReOning CO. Core-Tests Sulfur Deposits Off-Sharelauisiana
INDUSTRIAL A N D ENGINEERING CHEMISTRY
F
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ENGINEERING, DESIGN, AND PROCESS DEVELOPMENT
Geographical Distribution of Uranium and Thorium Ores Although we know even less ahout the true extent of the existence of petroleum than we do of coal, $1 the evidence indicates that we are gradually approaching an economic asymptote for both oil and gas. We drill deeper each year and, despite improved geophysical prospecting, must drill increasing numbers of wells per million b m l s of new reserves discovered. We are extending the drilling onto the continental ocean shelf with increasing difficulty and cost. Secondary recovery by pressurizing or using geophysical laxatives is successful in some fields, again at increasing coats. Already upward-creeping costs have forced the United States to import nearly 10% of ita crude petroleum. The arguments used in arriving at a plausible figure for practical reserves is devious and tedious, hut the results of one analysis are summariaed in Table V. The estimates given do not include any substmtial factor for offshore reserves beyond those now being tapped, as high costs will prohibit or limit recovery. Oil shale and tar sands are other significantsources of liquid and gaseous fuels, but here again recovery costs are high. Practical reserves of fossil fuels, realistically weighted by economic factors, are given in Table VI.
Table V.
Net Heat Content in Reserves of Fossil Fuels
(Suhatantiallv' oresent ooste and adjusted for loss in auntheaia) Heat Content. B.t.u. X 10" United state. World 21.0 3.1 Coal 5.0 0.5 Oil and gas 1.0 0.4 Oil shale 0.2 ... Tar sands -1 4 7 Total
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Table VI.
Plausible Miscellaneous Contributions to World Energy Input (Costs no greater than twice preaent aosts) Possible Annual sovroe Contribution, B.t.u. X 10"
Wood Farm waatea Wind power Solar power oolleotora Temp. diu. tropical water8 Tides Natural stream Earth'a heat Wave8 Atmoa herlo electricity C o d l e d biologics1 synthesis Heat pumps Total
1.5 1.0
0.1 0.05 0.05
0.025
0.w1
... ... ... ...
Nil 2.726 X lO'B.t.u./year
If a practical reserve of 4.0 X 1018 B.t.u. of fossil fuel for the United States is reasonably correct, it appears that we haveabout a century of grace before depletion and worry, because our current rate of consumption (largely fossil fuel) is only 0.036 X lo'$ B.t.u. But that would he a spurious and dangerous argument. Our population is inevitably rising rapidly and the per capita energy consumption will almost certainly continue to increase. Moreover, natural resources do not come forth from the earth at full blast to the very end. They dribble out and taper off. Putnam ( 5 ) summarizes the probable situation in this mannw for the United States. Some may contend that these data are unduly pessimistic and that the situation is not as bad as pictured. If this ba true, a reinvestigator might materially shift the figures well into the optimistic side of the spectrum. But if they keep the world necessity of low cost energy in mind and remember rising population and increasing per capita energy use, they will not shift the time scale a great deal. The reprieve from the critiosl dates
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 46, No. 12
l&EC LECTURE SERIES-Fufure
Energy Sources
would probably not be more than a decade. Thus, looked at peseimisticelly or optimistically, this generation appears to have a new problem that it cannot simply hand on to posterity. 2. Nuclear Energy. Atomic iission for power purposea is now growing aut of the dream and fad stage and steadily coming closer to reality. The potential supply in economically recoverable uranium and thorium appears to be over twenty times greater than that from fossil fuels. If other materials and other nuclear reactions can be harnessed and controlled, the eventual potential energy supply appears to be almost infinite, 8 8 messured by human standwds. To say that this area calla for more research is a gross understatement. Nuclear plants as presently visualized can produce sensible heat which can be used &s such or fed ta heat engines to produce electricity, It does not meet the well-implanted demand for liquid fuels. Therefore, even if the supply is great and widespread, it will probably not provide the eventual, universal solutiou.
1. Solar Energy. Solar radiation reaching the earth's Burface amounts to about 32 X 10mB.t.u. per year based on 62'/~0/, transmiaaion through the atmosphere. Present input to the world's human energy System is about 101' B.t.u. per year. Hence 32,000 times as much energy fall8 on the earth 8 8 we are now utilining in all human devices. Expressed another way, if we could harness, at 100% efficiency, all the solar energy that falls on a little more than 6000 square miles of the earth's surface, we could supply all our current needs. That would be a plot of ground somewhat less than 80 miles s q u a r e j u s t about enough to accommodate a military guided missile range, and the supply is perpetual-at least for a few million years. The direct harnessing of solar energy, therefore, appears to be an attractive proposition, but the idea loses some of its sheen ou oloser inspection. We still lack the knowledge which will enable us to make dective use of solar energy. But our ignorance should not be transformed into despair. Meeting such a situation is, I submit, what research men and engineers were made for.
Sunlight, Converted into Electricity by Bell Laboratories Solar Battery, Provides Power to Turn a Motor-Driven
Wheel
The World Musf Be Educafed l o f h e Problem and l o t h e Research and Development Task
Within recent years many leaders of business and industry well ss research men have been netring the conclusion that we are perbaps a bit unbalanced; that our know-how outruns our knowledge; tbrtt we may be well on the way to outsmarting ourselves; and that something should be done about it. Hence it is becoming inoressingly fashionableto beat the drum for fundamental research. This is all very well, but it is not sufficient. Not only must the fine words be backed with deeds (particularly financial support), but new technologies must be developed to match new research findings. Unless sound engineering developments follow closely the researcher's results, serious technological lags develop. Hence, the course of events from the gleam in the research man's eye to eventual utilisatioo of findings by the public is long, arduous, and expensive. However, we must postpone worrying about new technologies a bit, for the weakest part of our present position is in a lack of fundamental knowledge. Problems of engineering development and commercial exploitation will probably be solvable when we determine just what it is we are trying to do. Some quantum-jump advances appear to be needed in the next few decades.
Whenever it appears that an improvement or extension of an existing technology can lead to increased profits, financial and adminiatrative resources are usually available for exploitation. This ever-present economic drive is the basic strength of a competitive, capitalistic society. For this reason, American industry will probably evolve the most effectivemethods of recovery and utilization of our energy sources within the present technology. But for the future, the current state of the art and pattern of industrial development and exploitation will probably not be adequate to meet energy needs. The smaller the chance of ultimate s u c c ~ and s the longer the time msle for accomplishment, the leas likely is industry to foster a new idea. There are few businessmen who are or can aMord to be interested in heavily backing a 108to-1gamble that might pay off 25 or 30 years from now. For this reason we tend to remain myopic in the presence of a problem an difficult and slow-moving as the world's energy SUPPIY.
Fossil Fuels. We have been burning things for several thousand years, but we still do not have any very exact understanding of the pmess of combustion. Several research projects on the kinetics of combustion are under way, but we are still a long way from solid answers. Since efficiencies of combustion are already quite high in most processes, would we reap any substantial, quantitative benefits if we had a true understanding of the chemical kinetics involved? I have no way of knowing the answer to this, but scientific discoveries usually prove to be useful. The idea of direct oxidation of carbonaceous materials in an electrochemical cell has been toyed with for a century, but there has been but little serious research on the matter. Organic materials are particull~dystubborn in resisting this type of oxidation, but no one bas really proved that it cannot be done. Until) then, this should be s toppriority research project. Fundamen-' tal chemical and physical research of a high order must be
incipal disadvantages of solar energy are: The sup s intermittent. ration of energy (potential) The cor is low. i t s available form it has but limited utility. xaae i s a problem.
December 1954
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ployed to arrive at the answer. If an oxidation cell for coal il could be developed to produce electricity a t an efficiency of or 90%, the life and utility of foasil fuels would he changed ly. The inherent thermodynamic inefficiencies of heat would be avoided for many applications, and the result more kilowatt hours per pound of fuel. Higher effiincrease the real value of fossil 't would thus become econornicdly r hard-to-recover deposits. This, practical fossil fuel supply severale are those who fear d gas will BOOn remove a syntbetic chemicals. In t least for a few centuries.
that our proagate uee of cod, oil, most valuable raw material source my opinion this fear is unfounded, There is a built-in economic canustrial economy the real value per cals and coal chemicals will always the per pound value of fuel. Thus chemical industry can come from couomically feasihle for fuel B O U I C ~ ~ . at research pointed toward more use of eeteriaus to the companion chemical
Nuclear Energy. Stimulated hy both military and potential commercial needs, engineering research and development are proceeding at a rapid pace in the nuclear field. Practical nuclear-propelled submarines and nuclear stationary power p h t B will soon be realities. Very large nuclear-propelled aircraft for special uses are probably coming, though at least several years in the offing. Since developments are moving rapidly and since the deposits of uranium and thorium are enough far at least a few centuries, it,might be concluded that there is no need for research other than that now being carried out. Such a concluaion would, I believe, be erraneous. The adaptation of the fission rertetion (the atomic bomb) to military nee& had a profound quantitative and qualitative impact on warfare. The development of the fusion reaction (the hydrogen bomb) has had a more-or-less literally earthshaking, quantitative impact. An analogous pattern will probably hold for peaceful commercial applications. Using uranium (or perhaps thorium), heat and electric power production by nuclear
n
proceaw are almost economically feasible. If a fuaion reaction (not necessarily tbe hydrogen bomb reaction) could be adequately controlled, the production costs of large blocks of power might take a sharp drop. Not only would this expedite widqread use of nuclear power-it might introduce desirable, large scale new uses of energy (such as irrigation water from aea water) and open a new economic and social era. Undoubtedly research orienbd toward oontrolled fusion reactions is under way, but I doubt that it is receiving as much emphasis as it should. Whenever nuclear power is mentioned, the specter of the sbielding problem immediately arises. With our present knowledge the heavy shielding required for huniane verges the imprttctid for many applicatioua, such &B medium-sized airplanes; it seem to have relegated nuclear propelled automobiles to perpetual limbo and makes the nuclear railroad locomotive doubtful. Can effective radiation shields that are one or two orders of magnitude lighter in weight he made? Preaent-day physicists RW no really promising possibilities. But we need to h o w a great deal more about the nucleus itself before any anmer can be considered final. At present automobilef are the most avid usem of liquid fuel. If nuclear reactom are not practical for automobiles, for a variety of remns, there may still be demand for liquid fuel, and there may not he any supply. However, the situation could be altered by a device (weighing not more than 300 pounds) that could store enough electrical energy to propel an automobile for 500 miles. Present-day electrochemical storage batteries are at leaat an order of magnitude from meeting this performance. Is there some other approach that has not been explored? Might the answer be forthcoming from some ohaure of reaearch in solid state physics? Is there a possibility of developing a feasibleprocess for directly converting the energy of the radiation and particulate producta of fission or fueiou into electric energy? Here again physicists are gloomy, hut into what strange fields and dietant ~ s e s sof research must we look to 6nd out?
Solar Energy. The sun will always be with ua, giving forth thousands of times as much energy 88 we need. It can be had for the taking. There is no txa or uae charge, and I BBBume there never will be. But to use it effectively may require the most expensive and extensive research we have yet undertaken.
ilowott Pilot Plant Designe y North American Aviation fc ie Atomic Energy Commissic eat produced by atomic fl9sion pro s in reactor (left) is absorbed by quid metal passing through the reo I core. The metal is then piped to oter boiler (lower center) and rtea ill drive a turbine generator (canto
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Vol 46, No. 12
l&EC LECTURE SERIEWuture Energy Sources
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BOX SCORE ON "INCOME" ENERGY SOURCES FUEL WOOD
small: depends on forest management programs
FARM WASTES
small, uncertain, diminishing
WATER POWER
small, but might expand 15 to 20 times
SOLAR HEAT COLLECTORS
domestic heating: in limited use; plausible for significant use in middle and lower latitudes cooking: in use in India; may be useful in fuelless regions hat water. heating:' in use in Florida and the Southwest; small. air conditioning: might be economically justified in India and similar regions refrigeration: possibilities not attractive
SOLAR POWER COLLECTORS
may be useful for smoll loads; generally unattractive unless backed up by stored water
__ HEAT PUMP
future good, butcontributionto total is insignificant
WIND POWER
tried in U.S.S.R., United States, Greet Britain; apparently econotrically justifiable in the 2- to 100-kw. range in certain areas
The obvious m c h need is to find out more about photoWedonotwant merelytoduplicatewhattheplantsda, for even under the beat conditione plants are hardly more than 2% efficimt aa energy starers. .Ie it possible to develop a highly e5icientpmce8~ that doee not use biological materiale but produces organic materials usable aa liquid fuels? Or ia it necessary to m e organic materials at all? There has been sustained interest in research on photosynthesis in various places for many years, but adequate answers to these questions have not been fortbcoming. Much more basic understanding of wme phases of chemical kinetics and physics is needed before we will have a chance to 6nd reasonable mawem. Recent reports indicate that a photocell has been made that converts solar energy directly into electrical energy with an etficiency za high as 6%. Is it possible to increaae its efficiency tenfold? If the answer eventually proves to be yea, can practical devices be made to produce electrical power at reasonable cost? Even the lowly thermocouple may still have eome poeaibilities. Thermodynamic ef6cienciee of over 3% have been reported in oonvertii the disordered motioqof thermal energy into the ordered motion of electrical energy. Can this be greatly improved? a thermocouple work anyway? I aasume that these What &ea we probleuIa of solid e b t e physics about which we know but little. Serious developments are under way to adopt the greenhouse technique to carry the full load of cdmfort heat for buildings in moderate olimates. This calls for very subtantial heat storage capacities. Heat reservoirs such aa the eensihle heat of water and the heats of hydration of certain salts have been explored but are not particularly aatiafadory. Gan something better be devised? This appears to be an engineering rather than a reaearcb problem, but completely new research approacbes should not be overlooked. Smces of Support. The research items discussed here are intended aa a partial list of suggestion%. Solutione to long-tiu energy probleme will come only through research, largely I fundamental character, in are= that may i n i t i i appemto Lsynth-.
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Decermber 1954
far removed from the eventual application. There must be support and encouragement for strange projects that will not seem sensible to many Congressmen, businese executiva, or even aome research directors. Within recent yeam the attitude of many industries toward the role of research has changed substantially. Instead of insistence on complete attention to quiok %year developments, considerable support ia being given to 5- and 10-year research progrttms. This 18 a hopeful sign, but the trend baa not yet developed sufficiently to make inroads on the solution of basic energy problems. It is inevitable that the Federal Government will be active in the research for future ~ourcesof energy. But it will take more support and more Congressional enthusilurm than haa been evidenced thus far for the National Science Foundation. University laboratories will surely take a major part io the work and, although university research budgets are usually meager, some of the available reaourcw may be vectored t o w d these problems. Research foundatione can ale0 be very helpful. There is no one door to be opened for the necesetwy support; eventually all poasible on? will be utiliaed They will start to open when a few important people and intelligent sections of the general public rediae that the time of trouble for energy supplies appears to be much closer than we had formerly been led to believe. Then there will come a general recognition that something should be done about it and that the time to start ia just about now. Literature Cited (1) campbell,
M. R.,"u: B i ' ~ W d i & i ~ dS W ~ Y . Wbshiogton zs.
D. C., "Co~t6lMM&b t o Economic O e o l o ~ , "Psrt 11. 1909. (a) ~ m d r i c ~ A. s , .SUP^. ~ DOCUUIEU~, 8.GOV~. print- MW. .., Wsahmgton 25, D.C.. "Cod Resources. Energy Bournes. and Nation+ Policy." 1939. (3). pUtnmi. ,P.'C.. "Enerey in the Future." Vsn No,&rmd, York. 1853. EDITOR'S NOTE-We ackn D. VM I?ostrmd & Co. to other information from "Ener
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