Long-chain aliphatic nitriles in pyrolysates of young kerogen: implications for the intermediates in petroleum hydrocarbon formation.

Abstract

Gas chromatographic/mass spectrometric examination of products from laboratory thermal degradation of kerogen from a young marine sediment (Tanner Basin off California), revealed a series of long-chain nitriles whose carbon-chain lengths range from 12 to 26. These compounds appeared after the relatively mild thermal conditions of 310-350°C for 5-116 hrs and disappeared before major n alkane generation. We hypothesise that n-alkanes are generated at the expense of long-chain fatty nitriles which in turn are formed via fatty acid amide-linked structures in kerogen.Heating of standard long chain (C18) fatty acid amides with kerogen produced n-alkanes with no odd/even predominance. The heating experiments showed that these nitrogen compounds have a strong potential for producing a series of normal hydrocarbons. Consequently, nitrogen-linked long methylene-chain structures in kerogen analogous to fatty acid amides /fatty nitriles can act as one of the precursors of petroleum hydrocarbons.

Microstratigraphic, lipid biomarker and stable isotope study of a middle Palaeolithic combustion feature from Axlor, Spain

“… 46 The absence of n -alkyl nitriles also suggest that if there was combustion, it was performed at low temperatures (<350°C), not high enough to produce n -alkyl nitriles. 13 , 47 , 48 This is consistent with the predominance of long-chain odd n -alkanes 13 , 23 and the absence of low CPI (∼1) and low ACL (<24) values, indicative of combustion temperatures ≥300°C 21 , 22 , 23 …”

Artificial Maturation of Iron- and Sulfur-Rich Mars Analogues: Implications for the Diagenetic Stability of Biopolymers and Their Detection with Pyrolysis–Gas Chromatography–Mass Spectrometry

“…N-containing compounds including pyrroles, pyridines, and indoles are the pyrolysis products of proteins (Reeves and Francis, 1998 ). Alkylnitriles are possibly produced as an intermediate during the breakdown of N-containing compounds (such as fatty amides and fatty nitriles) to n -alkanes (Ishiwatari et al, 1992 ).…”

Novel Route to Erucamide: Highly Selective Synthesis from Acetonitrile at Room Temperature via a Photo-Fenton Process

“…Fatty acid N-derivatives, i.e., fatty acid nitriles and fatty acid amides, are considerably important molecules in the areas of chemistry − as well as biochemistry. − These molecules are present within living cells − and bear renowned applications in industry ,,− ,− in addition to therapeutics. ,,− The reported synthetic strategies include pyrolysis of biodegradable organic matter ,,− and ammoniolysis of fatty acid precursors, ,− involving extremely high temperatures up to 700 °C. However, there is a sole example that has reported the use of low temperature instead (50 °C using fatty ester) .…”