On the mechanism of the generation of petroleum Citation for published version (APA): Jurg, J. W. (1967). On the mechanism of the generation of petroleum. Pasmans. https://doi.org/10.6100/IR108998 DOI: 10.6100/IR108998 Document status and date: Published: 01/01/1967 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license above, please follow below link for the End User Agreement: www.tue.nl/taverne Take down policy If you believe that this document breaches copyright please contact us at: [email protected] providing details and we will investigate your claim. Download date: 26. Sep. 2021 ON THE MECHANISM OF THE GENERATION OF PETROLEUM PROEFSCHRIFT TER VERKRIJGING VAN DE GRAAD VAN DOCTOR IN DE TECHNISCHE WETENSCHAPPEN AAN DE TECHNISCHE HOGESCHOOL TE EINDHOVEN, OP GEZAG VAN DE RECTOR MAGNIFICUS, DR. K. POSTHUMUS, HOOGLERAAR IN DE AFDELING DER SCHEIKUNDIGE TECHNOLOGIE, VOOR EEN COMMISSIE UIT DE SENAAT TE VERDEDIGEN OP DINSDAG 26 SEPTEMBER 1%7, DES NAMIDDAGS . OM4UUR DOOR JAN WILLEM JURG GEBOREN TE 'S-GRAVENHAGE DRUKKERIJ J. H. PASMANS · 'S-GRAVENHAGE Promotor: Prof. Dr. G.C.A. Schuit 3 CONTENTS Chapter l GENERAL INTRODUCTION. 5 l Current opinions on the generation of petroleum. 5 a. Introduction. 5 b. Abiogenic theories. 5 c. Dual abiogenic-biogenic theories. 6 d. The biogenic theory. 8 e. Possible petroleum progenitors. 9 f • The radio-activity theory. 10 g. The "cracking" theory. 11 2 Background of the investigation. 12 Chapter 2 EXPERIMENTAL DETAILS. 16 l Introduction. 16 2 Hydrocarbons. 16 3 Fatty acids. 18 Chapter 3 RESULTS. 20 l Low-molecular-weight hydrocarbons. 20 a. Experiments without water. 20 b. Experiments with water. 27 2 High-molecular-weight hydrocarbons. 29 3 Fatty acids. 31 Chapter 4 SOME ASPECTS OF THE CRACKING REACTIONS. 34 1 In trod uc tion. 34 2 Thermal cracking. A radical mechanism. 34 3 Catalytic cracking. A carbonium ion mechanism. 36 Chapter 5 DISCUSSION OF THE RESULTS AND CONCLUSIONS. 38 l From the experiments without water. 38 2 From the experiments with water. 38 3 The mechanism of the formation of long chain n-alkanes and fatty acids. 39 4 Geochemical consequence of the results. 44 SUMMARY. 46 SAMENVATTING. 48 REFERENCES. 50 4 My sincere thanks a~e extended to Drs. E.Eisma, Head of the Geochemical Research Section of the Koninklijke/Shell Exploratie en Produktie Laboratorium in Rijswijk, for introducing me in the field of geochemistry, for his stimulating interest in this investigation and for the many valuable discussions. 1 want to express my gratitude to my colleagues for the pleasant co-operation and for their suggestions. I am especially grateful to Mr. J .A •. Gransch for critically reviewing the manuscript, to Miss E.B.I. de Rijk, Mrs. H.J. de Veer-Rgmbat and to Mrs. J .Lindeman­ Stuiver for their aid and enthusiasm in performing the experiments. I wish to thank the directors of Shell-Research N.V. and the directors of the Koninklijke/Shell Exploratie en Produktie Laborato­ rium for their permission to publish the work in this thesis. I am indebted to the Permanent 'council of the World Petroleum Congresses, which was so kind as to waive the copyright of some illustrations. 5 CH.APTER 1 GENERAL INTRODUCTION 1 Current opinions on the generation of petroleum. a, Introduction. The origin of petroleum is still a matter for discussion. The preponderance of available evidence supports the "organic" or "bio­ genic'' school, which adheres to the theory that petroleum has been formed by conversion of plant and animal remains deposited together with fine grained minerals at the bottom of the sea or a lake. Never­ the less, there are those who are not impressed by the arguments advanced by the biogenic school and who adhere to the 11 inorganic" or 11 abiogenic" theory, according to which petroleum was synthesised in processes involving no living organisms. Some facts concerning the generation of petroleum, however, have not found an explanation by organic chemical arguments. This is the reason why several in­ vestigators show interest in a dual biogenic-abiogenic hypothesis for the origin of petroleum. The purpose of this chapter is to give a summary of the current opinions on the origin and generation of crude oil. At the end of this chapter a survey is given of the particular aspects found in literature which lead us to our investigation: the generation of hydrocarbons from a straight-chain fatty acid. b. Abiogenic theories. In 1866 BERTHELOT ( l) suggested that carbides are the pri­ mary source for petroleum. The reaction of alkali metals with car­ bonates resulted in carbides which would react with water to produce acetylene. The generation of petroleum from acetylene was ascribed to high pressure and temperature. A similar theory was described by MENDELEJEFF (2) who also proposed that acetylene was generated as a result of the re­ action of carbides with water or acids and formed petroleum. According to a recent suggestion by MARX (3) graphite is a possible source for petroleum. Since graphite is a conductor it acts as one electrode of a voltaic cell in which water will be decomposed. 6 The generated hydrogen reacts with the graphite to form numerous hydrocarbons. Marx suggests that ferrous sulfide could act as an anode which will be oxidized into ferric oxide. The difficulty that the stand­ ard free energy change for the overall reaction is +41 Cal. is ex­ plained away by assuming the upward migration of the hydrocarbons, which would reduce the concentration of the hydrocarbons in the cell to such an extend that the reaction could proceed. The similarity which exists between the low-molecular-weight hydrocarbons in crude oil and those in Fischer-Tropsch catalytic synthesis products prompted FRIEDEL and SHARKEY {4) to the suggestion that· the volatile components of crude oils could have originated from such synthesis reactions. They remark, however, that this similarity is no evidence for an abiogenic origin of petroleum. On the basis of astrophysical evidence of the presence of radic­ als, like CH 3 , in the sun, KUDRYAVTSEV (5) advanced the theory that these radicals are also formed in deep-seated zones of the earth by a direct synthesis of H and C.Penetrating into the cooler parts of the mantle of the earth these radicals would combine with each other and with H to form petroleum-like compounds. Other authors who held t~~ view that petroleum hydrocarbons are of abiogenic origin are CLOEZ {6), SABATIER and SENDERENS (7), TERSIL'YE (8) and PROSKURY AKOVA (9). c. Dual biogenic-abiogenic theories. WILSON (10) adapted the view that the primitive material from which the earth was formed contained a small percentage of high­ molecular-weight hydrocarbons, as do some meteorites falling on the earth nowadays. These hydrocarbons underwent thermal cracking and the cracked products would flow through porous strata, picking up, by solvent extraction, small quantities of materials of biogenic origin. Petroleum often contains large quantities of straight-chain hydrocarbons and a basic part of Wilsons hypothesis is that straight chain hydrocarbons can be produced by a non-biological mechanism. Wilson assumed that the straight chain hydrocarbons can be produced via a free radical mechanism from methyl radicals. The proposed mechanism involves the assumption that the chains are crowded on a surface so that only the ends are available for reaction, thus pre­ venting branching. Laboratory experiments of WILSON and JOHNSON (ll) demonstrated that palmitic acid can be build up stepwise to n-nonadecanoic acid in a reaction from methyl radicals with palmitic acid. According to GLOGOCZOWSKI ( 12) there reigns deep in the 7 earth a reducing environment, formed by gases like hydrogen and carbonmonoxide. With certain inorganic minerals as catalyst these gases are transformed under high pressure and temperature to hydrocar­ bons. When the pressure of the generated hydrocarbons surpasses the overburden load, migration can start. During the transport biogenic substances are dissolved. An examination of the available evidence convinced ROBINSON ( 13) that petroleum hydrocarbons are both of biogenic and abiogenic origin. He agrees that the evidence for the biogenesis is uncontrovert­ ible, but only holds for a part of the material. He states that it cannot be too strongly emphasized that petroleum does not represent the picture expected about the composition of modified biogenic products alone. The composition of ancient oils fits equally well with that of a primordial hydrocarbon mixture to which bio-products have been added.