The role of alkenes produced during hydrous pyrolysis of a shale

نویسنده

  • Roald N. Leif
چکیده

Hydrous pyrolysis experiments conducted on Messel shale with D2O demonstrated that a large amount of deuterium becomes incorporated into the hydrocarbons generated from the shale kerogen. In order to understand the pathway of deuterium (and protium) exchange and the role of water during hydrous pyrolysis, we conducted a series of experiments using aliphatic compounds (1,13-tetradecadiene, 1-hexadecene, eicosane and dotriacontane) as probe molecules. These compounds were pyrolyzed in D2O, shale/D2O, and shale/H2O and the products analyzed by GC±MS. In the absence of powdered shale, the incorporation of deuterium from D2O occurred only in ole®nic compounds via double bond isomerization. The presence of shale accelerated deuterium incorporation into the ole®ns and resulted in a minor amount of deuterium incorporation in the saturated n-alkanes. The pattern of deuterium substitution of the diene closely matched the deuterium distribution observed in the n-alkanes generated from the shale kerogen in the D2O/ shale pyrolyses. The presence of the shale also resulted in reduction (hydrogenation) of ole®ns to saturated n-alkanes with concomitant oxidation of ole®ns to ketones. These results show that under hydrous pyrolysis conditions, kerogen breakdown generates n-alkanes and terminal n-alkenes by free radical hydrocarbon cracking of the aliphatic kerogen structure. The terminal n-alkenes rapidly isomerize to internal alkenes via acid-catalyzed isomerization under hydrothermal conditions, a signi®cant pathway of deuterium (and protium) exchange between water and the hydrocarbons. These n-alkenes simultaneously undergo reduction to n-alkanes (major) or oxidation to ketones (minor) via alcohols formed by the hydration of the alkenes. # 2000 Elsevier Science Ltd. All rights reserved.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Generation of water-soluble organic acids from kerogen during hydrous pyrolysis: implications for porosity development

Concentrations of organic acids ranging up to several thousand parts per million have previously been found in oil-field waters. These acids are of interest because of their potential to enhance porosity by the dissolution of carbonates and aluminosilicates. They are believed to be generated from organic geopolymers (kerogen) in the late-diagenetic-early-catagenetic stage of thermal maturation....

متن کامل

کانی‌شناسی و زمین‌شیمی کانی‌های آبدار سولفاتی وابسته به شیل‌های سیاه منطقه قروقچی، میمه، استان اصفهان

Qroqchy area is located northwest of Isfahan, in the central Iranian structural zone. The Nayband black shale is a significant geological unit which is widespread occurrences in the study are. Weathering process lead to black sale alteration and formation of acidic pool. The pool is located on the black shale basement. Around of the pool sulfate minerals occur with various colors. The aim of th...

متن کامل

Vaporization Parameters of Primary Pyrolysis Oil from Kukersite Oil Shale

The objective of this study was to obtain vapor pressure and heat of vaporization values of the less volatile heavy end of the Kukersite oil shale primary pyrolysis oil and therefore to have a quantitative insight into the vaporization ability of the oil during the pyrolysis process. The shale oil was produced via rapid pyrolysis in a laboratory scale reactor and collected in a solvent filled c...

متن کامل

A Novel Energy-Efficient Pyrolysis Process: Self-pyrolysis of Oil Shale Triggered by Topochemical Heat in a Horizontal Fixed Bed

This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250-300°C), the hot air can be replaced by ambie...

متن کامل

Geochemical Characteristics and Hydrocarbon Generation Modelling of Early Triassic to Late Cretaceous Formations within Ogaden Basin, Ethiopia

The major goal of this study is the evaluation of the source rock of Ogaden Basin using Rock-Eval Pyrolysis, Vitrinite reflectance (%Ro), and well log data of the Permo-Triassic and the Mesozoic sequences including Karro, Hamanlei, and Urandab Formations. Burial history and level of thermal maturity of the Bodle-1 well, the Calub-1 well and the Hilala-2 well were modeled based on the calibratio...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2000