DBPapers
DOI: 10.5593/sgem2017H/15/S06.077

THERMAL DECOMPOSITION OF TYPE-II KEROGEN: JOINT THERMOGRAVIMETRIC AND FTIR STUDY

D. Emelianov, V. Agieienko, M. Varfolomeev, Vakhin A., C. Yuan
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-26-3 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 15, 607-618 pp; DOI: 10.5593/sgem2017H/15/S06.077

ABSTRACT

The consumption of oil for human needs is increasing in the modern word. With that needs, it is important to use the conversion of the alternative sources of hydrocarbons. One of the promising sources of them is an oil shale. It is possible to convert this substance via pyrolysis or combustion. The possible degree of conversion of this remarkable biopolymer with the nature origin can reach 40%. Recently, thermal analysis techniques have been widely used for investigation of the oil shale oxidative and inert degradation. Their simplicity and an additional opportunity to carry out simultaneous spectral analysis allow one to get more details on the combustion and pyrolysis mechanism.In the present study we use thermogravimetry equipped by FTIR spectrometer for analyzing the emitted product gases to investigate the pyrolysis of Bazhenov formation kerogen. The studied samples were preliminarily purified from bitumen fraction and demineralized from calcite and silicate matrices. The measurements were performed in the temperature range 25-800 °C in inert (nitrogen) atmosphere. To estimate the pyrolysis process kinetic characteristics the measurements were performed at 5, 10, 15, and 20 K min-1 heating rates. It was shown that the TG curve includes two mass loss stages. In order to study the rock influence on the kerogen pyrolysis, the 15 / 85 (w/w) kerogen / calcite mixtures were also investigated. In agreement with the earlier work by Pan et al. It was shown that calcite has no significant influence on the kerogen pyrolysis. For example, the position of the principal peaks on the DTG curves (decomposition of kerogen and pyrite) do not shift in the presence of calcite. The activation energy, however, shows some decrease compared to the value found for the kerogen pyrolysis in the kerogen-pyrite mixture. The effect of MnO2 additives (1% wt.) – promising nanocatalyst – on the thermal behavior and kinetic parameters of kerogen was also thoroughly studied.

Keywords: TG-FTIR, Kerogen, Pyrolisis, crude oil recovery, kinetics