Chemical & Engineering News 1155—16th St., N.W., Washington, D.C. 20036 Editor: Michael Heylin Assistant Managing Editors: David M. Kiefer, James H. Krieger, Janice R. Long, Donald J. Soisson, William J. Storck Staff Editor: Ernest L. Carpenter Senior Editors: New York: Earl V. Anderson; Chi cago: Joseph Haggin; Washington: Lois R. Ember, Wilbert C. Lepkowski, Rebecca L. Rawls, Howard J. Sanders Associate Editors: Doron Dagani, Bette Hileman, Richard J. Seltzer, Pamela S. Zurer Assistant Editor: Mairin B. Brennan Service Departments Editor: Theresa L. Rome Editing Services: Joyce A. Richards (Head), Dolo res Miner (Editorial Assistant), Patricia Oates (Program Assistant) News Bureaus: New York: (212) 697-3223 David Webber (Head), Stephen C. StinsOn (Associate Editor). Chicago: (312) 256-4143 Ward Worthy (Head). Houston: (713) 973-8161 Bruce F. Greek (Head). Washington: (202) 872-4495 David J. Han son (Associate Editor). West Coast: (415) 653-3630 Rudy M. Baum (Head). Foreign Bureau: London: (01) 540-0414 Dermot A. O'Sullivan (Head), Patri cia L. Layman (Associate Editor) Graphics and Production: Elmer M. Pusey Jr. (Head). Leroy Corcoran (Manager). Alan Kahan (Art Director). Barbara Fryer (Production/Art Di rector). Linda Mattingly (Staff Artist). Diane K. Lilienkamp (Costing). Business Manager: Arthur Poulos Circulation Development: Cynthia G. Smith ADVISORY BOARD: William J. Bailey, Myron Foveaux, Harry B. Gray, Vincent L. Gregory Jr., John D. Holmfeld, Donald F. Hornig, Isabella Karle, W. Thomas Lippincott, John M. Logsdon, Dorothy Nelkin, Richard Nicholson, Howard A. Schneiderman, Ellen K. Silbergeld, Howard E. Simmons, William P. Slichter, H. F. Tomfohrde III, Mark S. Wrighton, Richard N. Zare Published by AMERICAN CHEMICAL SOCIETY (202) 872-4600; TDD (202) 872-8733 John Κ Crum, Executive Director EDITORIAL BOARD: Barbara G. Wood (Chair man); Board of Directors Chairman; Paul V. Smith Jr.; President-Elect: Mary L. Good; immediate Past-Presi dent: Ellis K. Fields; Ernest L. Eliel; E. E. McSweeney; John H. Nelson; and Jean'ne M. Shreeve. © Copyright 1986, American Chemical Society Subscription Service: Send all new and renewal subscriptions with payments to: Director, Busi ness Management Division, ACS, P.O. Box 57136, Washington, D.C. 20037. Correspondence and telephone calls for changes of address, claims for missing issues, subscription service, status of re cords and accounts should be directed to: Manager, Membership & Subscription Services, ACS, P.O. Box 3337, Columbus, Ohio 43210; (614) 421-3776. Changes of Address: Include both old and new addresses with ZIP code numbers and mailing label from a recent issue. Allow four weeks for change to become effective. Claims for missing numbers will not be allowed if loss was due to failure of notice of change of address to be received in the time specified; if claim is dated (a) North America: more than 90 days beyond issue date, (b) all other foreign; more than one year beyond issue date; or if the reason given is "missing from files." Subscription Rates 1986. Printed editions: nonmembers U.S. 1 yr. $40,2 yr. $68, outside U.S. 1 yr. $65, 2 yr. $118. Air freight rates available on re quest. Rates above do not apply to nonmember subscribers in Japan, who must enter subscription orders with Maruzen Co. Ltd., 3-10 Nihonbashi 2chome, Chuo-ku, Tokyo 103, Japan. Tel: (03) 2727211. Single copies: Current $5.00. Rates for back issues and volumes are available from Microforms & Back Issues Office, ACS, 1155—16th St., N.W., Washington, D.C. 20036. Back and current issues available on microfilm and microfiche. Rates on request from Microform Program, ACS. Chemical & Engineering News (ISSN 00092347) is published weekly except for the last week in December by the American Chemical Society at 1155—16th St., N.W., Washington, D.C. 20036. Second-class postage paid at Washington, D.C, and additional mailing offices. POSTMASTER: Send address changes to Chemical & Engineering News, Membership & Subscription Services, P.O. Box 3337, Columbus, Ohio 43210. ACS assumes no responsibility for the statements and opinions ad vanced by the contributors to its publications. Advertising Management CENTCOM LTD. (For list of offices see page 83) 2
April 2 1 , 1986 C&EN
LETTERS
Biogenic and abiogenic petroleum SIR: The special report on "Geochemistry in the Search for Oil" by R. Paul Philp (C&EN, Feb. 10, page 28) presents many arguments that are supposed to s h o w h o w oil is formed from exclusively biological source materials in sediments. Although this viewpoint has gained widespread acceptance, it is mislead ing to present what are only hypotheses as securely established facts. All the observa tions usually invoked to support an exclu sively biological origin are also consistent with a duplex origin (abiogenic plus biogen ic) for petroleum. Furthermore, some wellestablished observations find no explanation in the conventional scheme, and alternative interpretations are possible. The demonstration that trace constituents of petroleum can be derived from biological source materials does not tell us that most of the petroleum is biogenic. Many of the chem ical transformations described by Philp—for example, the production of steranes from kerogen—may well occur in nature, but no amount of elaborating on the chemical de tails contributes in any way to demonstrating an exclusively biological source for the bulk of the petroleum, or indeed of the kerogen. "Biomarkers" or "molecular fossils" are supposed to have provided the strongest sup port for the biogenic viewpoint. Molecules that appear to derive from biological materi als are certainly present in most natural pe troleum. But w e k n o w of three ways in which they w o u l d be introduced e v e n if the bulk petroleum had a nonbiological origin. First, an impressive range of nonbiogenic complex organic molecules occurs in nature, closely resembling or overlapping the bio genic ones. Most can be produced in FischerTropsch-type syntheses (carbon monoxide and hydrogen gases reacting in the presence of common mineral catalysts at modest tem peratures and pressures); such reactions al most certainly occur in sediments through which deep source C-H-O-N gases are streaming. These products (including paraf fins, alkylbenzenes, porphyrin-type pig ments, condensed aromatics, and light isoprenoids) also occur in carbonaceous meteor ites, where a biological derivation is most unlikely. "If found in terrestrial objects, some substances in meteorites w o u l d be regarded as indisputably biological," chemist Harold Urey concluded in 1966. It seems that a spe cific set of complex organics is readily pro duced in geological environments with natu ral catalysts and that biology, w h e n it arose, adopted some of these for its o w n use. But for merely historical reasons, these organic sub stances are still widely regarded as specifical ly biological.
Second, sedimentary rocks generally con tain a w i d e spectrum of biogenic molecules. Many of these substances are soluble in oil, so that oil of whatever origin, trapped for mil lions of years in sediments, cannot avoid con tamination by such biomarkers. Third, biomaterials are introduced by mi crobial activity in oil. Recent observations, by Guy Ourisson and associates, that hopanoids (thought to be derived from bacterial cell walls) are present in almost all oils, imply that petroleum uncontaminated by bacteria is rare or absent, and therefore that other mole cules from these bacteria are bound to be in troduced also. Furthermore, selective micro bial metabolism can account for the observa tion that optical activity occurs only in lowtemperature petroleum. The chemical similarities between oils in a reservoir and in nearby source rocks are cited as confirming the assumption that all the car bonaceous material is biogenic and that the reservoir was supplied from this alleged source material. But it is by no means certain that this is the correct interpretation. If a sup ply of hydrocarbons from another source had reached both locations, this w o u l d also pro vide the observed relationships. The many forms of unoxidized carbon in the rocks, some of w h i c h are called kerogen, may have a biological component, but they may be due in major part to deposition by polymerization or physical absorption from hydrocarbons carried in upwelling fluids of deep origin. A m o n g observations not explained by the biogenic theory is the widespread association of hydrocarbons with helium and other no ble gases. All the world's commercial helium is produced from natural gas, principally methane. Biological processes certainly did not concentrate the helium, and all that can be said in the context of biogenic theories is that the helium collected beneath the same caprocks as contained the oil and gas. But there are many good traps that do not contain any petroleum. Why do those not contain similar amounts of helium as do the numer ous oil and gas traps? Why should substantial concentrations of helium only be found in the presence of petroleum? If the supply of helium were unrelated to that of hydrocar bons, then the distribution of the concentra tion should reflect the distribution of the quantities of the various gases foun,d in the traps, but this is not the case. A useful test of the biogenic theory is to examine h o w well it accounts for the single most spectacular occurrence of petroleum in the world. The Middle Eastern oil province (extending from eastern Turkey through Iran and Iraq to the Persian Gulf and Saudi Ara bia) constitutes only a few per cent of the world's land area but contains more than half of all k n o w n reserves. Most of the traps are
filled to overflowing with petroleum which their concerns and also to have disclosed to viduals in science and many other fields is chemically similar, despite the differing the media what was happening. They must make use of imagery and dreams (which I geological formations, ages, and depths. The have thought about this possibility, but the consider images obtained during sleep) can region has been explored extensively. Here probable reason they did not do it was for be attested to by a number of examples from surely, organic-rich sedimentary formations history. I believe the number is more extenfear of losing their jobs with MT and also of should be clearly in evidence. Unfortunately, the certainty that they would be blacklisted sive than is publicly acknowledged since, in geologists cannot agree on the identity of any and unable to get jobs again in their chosen science in particular, many people feel that adequate source rocks in this region, because such a source is suspect. Also, an image is field, at least only after very great difficulty. none of the candidates are particularly large What is needed is a tough federal law pro- often just the beginning inspiration or a in volume or rich in organics. A single deeptecting the job rights of professional employ- small part of a fully developed piece of work seated abiogenic source, however, could acees. This would be similar to the provisions and may have lost its significance by the time count for these observations. of the guidelines for employment of engi- the effort has taken its final form. Much of Laboratory experiments reported to yield neers and scientists which have been en- my attitude in this area comes from firsthand petroleum products from kerogen subjected dorsed by many engineering societies and information, including input from friends and colleagues. to hydrous pyrolysis should be regarded the professional employment guidelines of with some skepticism. They have been per- ACS. This could be dubbed the "Professional I was somewhat offended to find that Vanformed in a closed system, under hydrogen Bill of Rights." While there are provisions in derbilt, the self-proclaimed expert on creativpartial pressures much higher than would a number of federal laws extending this pro- ity, feels that the rest of us have "little knowlever be the case in nature; this favors saturattection to whistle blowers—and there are edge as to how new knowledge and new ed products. Plant material may well contribsome state laws directed to this area—there is things originate." Does he? His comparison ute to kerogen, but the pyrolysis of kerogen no overall federal law directed specifically to of Edison, a man of great practical genius but in an open system leads to hydrogen deplethis subject. who used the ideas of others, and Einstein, tion (graphitization), not to hydrogénation Why specifically for professional employ- who many feel took some of the greatest (petroleum). It is not even clear that the prodees? The reason is that this class of employees strides in scientific thinking, leaves me agiucts in such experiments are the result of generally has more to do with the design and tated. It is like comparing a Picasso to a phochemical transformation; some may be physicertification of processes and equipment and tocopying machine. Vanderbilt apparently cally desorbed from the kerogen in a process materials that might cause harm to the gener- feels that the patent is the ultimate determiakin to steam cleaning. al public or specific segments of the public. It nation of creativity. We agree with the conclusion of the distinis a class of employees that is so designated in I believe Vanderbilt is correct that "the guished chemist Sir Robert Robinson: "Acthe National Labor Relations Act and is spe- present-day scientist-engineer is more likely tually it cannot be too strongly emphasized cifically exempted from the provisions for to succeed by following the hard work apthat petroleum does not present the composithe Wages & Hours Act (so they have the proach of Edison." Most practical products tion picture expected of modified biogenic privilege of working overtime without pay) are produced by applying known principles products, and all the arguments from the and, generally, such employees do not be- to new applications in a creative way. That is constituents, of ancient oils fit equally, or betlong to unions. part of the success of the Japanese. These ter, with the conception of a primordial hyAlthough such a bill of rights would bene- tasks often don't require the creative leaps drocarbon mixture to which bio-products fit professional employees, it would also lay a that some can generate from dreams and imhave been added." burden of responsibility upon them and ages. But please, Byron, don't talk all the sciThomas Gold, Steven Soter would be for the benefit, primarily, of the entists of tomorrow out of following the hard work approach of Einstein and others. AlCenter for Radiophysics and Space Research safety and interests of the general public. Cornell University, Ithaca, N.Y. Alan C. Nixon though no significant achievement can be Past-President ACS (1973) attained without hard work, there are many Past-Chairman Council of Scientific Society sources for ideas and inspiration and we need Presidents (1973-74) them all since there are other needs in sciProfessional employee ence and society than the soaps and plastic protection toys of today. SIR: It is now reasonably clear from the meet-, Mark A. Adams, St. Louis Followup on Kekulé's dream ings of the Presidential Commission that the reason for the Challenger tragedy was the fail- SIR: I have followed the discussion on ure of NASA managers to pay attention to Kekulé's dream and its significance to science warnings from, particularly, Morton Thiokol with a good deal of humor. That individuals Additional work cited (MT) engineers who were directly concerned who find dreams and images unimportant in SIR: I refer to the article, "Materials Developwith the temperature limits under which the their own mental processes want to deny ments Highlight Progress in Batteries" solid rocket boosters could perform safely, their usefulness in general is foolish. The let- (C&EN, Dec. 16, 1985, page 23). The formaand that the MT management was reluctantly ter by Vanderbilt (C&EN, Feb. 24, page 2), tion of planar arrays of carbon atoms wrappersuaded by NASA upper management to however, represented such a narrow-minded ping the electrodes in concentric rings by certify the safety of operation of the solid and arrogant attitude, as to prompt me to special heat treatment has been described in rocket boosters below the minimum safe oprespond to him, as well as several other corre- my paper in Z. Anorg. Chem., 253,263 (1947). erating temperature, thus overruling the recOn June 20, 1955, German patent 929204 spondents. ommendation of its own engineers. This was The question of whether a dream was the was granted to Ulrich Hoffman and Gerhard clearly a situation in which MT engineers Ruess for this method to improve corrosion actual source of the idea for the structure of should have gone over the heads of their own benzene is one for the historians, and is not resistance of carbon electrodes. management and of NASA management to Gerhard L. Ruess the deciding factor in determining the imthe spacecraft commander and alerted him to Wiesenhof, Austria portance of dreams. That many creative indiApril 21, 1986 C&EN 3
