Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils
Апстракт
A detailed investigation of significance of the infrared (IR) spectroscopic branching factor (CH2/CH3; the ratio of methylene and methyl group peak heights at 2917-2921 and 2951-2954 cm(-1), respectively in the IR spectra) for characterization of alkane structure, geochemical properties and viscosity of 76 oil samples was performed. These oils, originating from 13 Serbian oil fields in SE Pannonian Basin, differ according to source and depositional environment of organic matter (OM), as well as by thermal maturity and biodegradation stage. Methylene and methyl asymmetric stretching peak absorbances were used for the branching factor calculation. CH2 peak positions exhibited 3-4 cm(-1) red shift with increasing the CH2/CH3 ratio, due to a greater contribution of trans vs. gauche rotamers in aliphatic chains. Comparing IR spectra of the oils and model n-alkanes, it was established that the average (CH2)(n) methylene chain length per CH3 group varied from n = 3.5 to 6.5. The CH2/CH3 ratio... showed significant concordance with geochemical parameters, enabling clear distinction of the oils according to source and depositional environment of OM. At the same time, dependence of the CH2/CH3 ratio on oil maturity in the range from immature to mature was not observed, allowing for an accurate determination of oil genetic types irrespective of maturity. The CH2/CH3 ratio showed good accordance with oil biodegradation scale and oil viscosity.
Кључне речи:
viscosity / Serbian oil fields / Pannonian Basin / oil genetic types / infrared spectroscopy / alkane branchingИзвор:
Journal of the Serbian Chemical Society, 2022, 87, 1, 41-55Издавач:
- Srpsko hemijsko društvo, Beograd
Финансирање / пројекти:
- Министарство просвете, науке и технолошког развоја Републике Србије, Уговор бр. 200168 (Универзитет у Београду, Хемијски факултет) (RS-200168)
- Министарство просвете, науке и технолошког развоја Републике Србије, Уговор бр. 200288 (Иновациони центар Хемијског факултета у Београду доо) (RS-200288)
DOI: 10.2298/JSC210830091S
ISSN: 0352-5139
WoS: 000768190400001
Scopus: 2-s2.0-85124492977
Институција/група
Institut za tehnologiju nuklearnih i drugih mineralnih sirovinaTY - JOUR AU - Stevanović, Jelena Z. AU - Rakitin, Anton AU - Kojić, Ivan AU - Vuković, Nikola AU - Stojanović, Ksenija PY - 2022 UR - https://ritnms.itnms.ac.rs/handle/123456789/637 AB - A detailed investigation of significance of the infrared (IR) spectroscopic branching factor (CH2/CH3; the ratio of methylene and methyl group peak heights at 2917-2921 and 2951-2954 cm(-1), respectively in the IR spectra) for characterization of alkane structure, geochemical properties and viscosity of 76 oil samples was performed. These oils, originating from 13 Serbian oil fields in SE Pannonian Basin, differ according to source and depositional environment of organic matter (OM), as well as by thermal maturity and biodegradation stage. Methylene and methyl asymmetric stretching peak absorbances were used for the branching factor calculation. CH2 peak positions exhibited 3-4 cm(-1) red shift with increasing the CH2/CH3 ratio, due to a greater contribution of trans vs. gauche rotamers in aliphatic chains. Comparing IR spectra of the oils and model n-alkanes, it was established that the average (CH2)(n) methylene chain length per CH3 group varied from n = 3.5 to 6.5. The CH2/CH3 ratio showed significant concordance with geochemical parameters, enabling clear distinction of the oils according to source and depositional environment of OM. At the same time, dependence of the CH2/CH3 ratio on oil maturity in the range from immature to mature was not observed, allowing for an accurate determination of oil genetic types irrespective of maturity. The CH2/CH3 ratio showed good accordance with oil biodegradation scale and oil viscosity. PB - Srpsko hemijsko društvo, Beograd T2 - Journal of the Serbian Chemical Society T1 - Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils EP - 55 IS - 1 SP - 41 VL - 87 DO - 10.2298/JSC210830091S UR - conv_937 ER -
@article{ author = "Stevanović, Jelena Z. and Rakitin, Anton and Kojić, Ivan and Vuković, Nikola and Stojanović, Ksenija", year = "2022", abstract = "A detailed investigation of significance of the infrared (IR) spectroscopic branching factor (CH2/CH3; the ratio of methylene and methyl group peak heights at 2917-2921 and 2951-2954 cm(-1), respectively in the IR spectra) for characterization of alkane structure, geochemical properties and viscosity of 76 oil samples was performed. These oils, originating from 13 Serbian oil fields in SE Pannonian Basin, differ according to source and depositional environment of organic matter (OM), as well as by thermal maturity and biodegradation stage. Methylene and methyl asymmetric stretching peak absorbances were used for the branching factor calculation. CH2 peak positions exhibited 3-4 cm(-1) red shift with increasing the CH2/CH3 ratio, due to a greater contribution of trans vs. gauche rotamers in aliphatic chains. Comparing IR spectra of the oils and model n-alkanes, it was established that the average (CH2)(n) methylene chain length per CH3 group varied from n = 3.5 to 6.5. The CH2/CH3 ratio showed significant concordance with geochemical parameters, enabling clear distinction of the oils according to source and depositional environment of OM. At the same time, dependence of the CH2/CH3 ratio on oil maturity in the range from immature to mature was not observed, allowing for an accurate determination of oil genetic types irrespective of maturity. The CH2/CH3 ratio showed good accordance with oil biodegradation scale and oil viscosity.", publisher = "Srpsko hemijsko društvo, Beograd", journal = "Journal of the Serbian Chemical Society", title = "Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils", pages = "55-41", number = "1", volume = "87", doi = "10.2298/JSC210830091S", url = "conv_937" }
Stevanović, J. Z., Rakitin, A., Kojić, I., Vuković, N.,& Stojanović, K.. (2022). Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils. in Journal of the Serbian Chemical Society Srpsko hemijsko društvo, Beograd., 87(1), 41-55. https://doi.org/10.2298/JSC210830091S conv_937
Stevanović JZ, Rakitin A, Kojić I, Vuković N, Stojanović K. Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils. in Journal of the Serbian Chemical Society. 2022;87(1):41-55. doi:10.2298/JSC210830091S conv_937 .
Stevanović, Jelena Z., Rakitin, Anton, Kojić, Ivan, Vuković, Nikola, Stojanović, Ksenija, "Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils" in Journal of the Serbian Chemical Society, 87, no. 1 (2022):41-55, https://doi.org/10.2298/JSC210830091S ., conv_937 .