Study of physical and chemical properties of vitrinites. Inferences on depositional and coalification controls

A. Jimenez (1) , María José Iglesias (1) , Fatima Laggoun-Défarge (2) , Isabel Suarez-Ruiz (1)

1 Instituto Nacional del Carbon
2 ISTO - Institut des Sciences de la Terre d'Orléans

A detailed study of petrological, geochemical, textural and coking properties was carried out on vitrains from the Puertollano, Blanzy–Montçeau, Asturias and Teruel. The objective was to determine in depth the physical and chemical properties of a series of natural and pure vitrinites of different rank, and the influence that the sedimentary and post-sedimentary conditions had on them. It is demonstrated that although vitrains are almost entirely made up of the huminite/vitrinite maceral group they have a different composition, thermal behaviour and physical properties. Thus, geochemical and textural properties of Blanzy–Montçeau vitrains can be considered to be representative of the telinite, the major component in both samples (75% vol.) at the beginning of the bituminization stage (subbituminous/high volatile C bituminous coals). The characteristics of the Puertollano vitrains described here can also be attributed to the telocollinite (>80% vol.) for the high volatile C bituminous coal. Variations in physico-chemical properties between Puertollano and Blanzy–Montçeau vitrains are due to the differences in the initial composition of organic matter. Slight differences (i.e., bed moisture content or porosity) between vitrains from the two coal seams in the same basin can be attributed to their stratigraphic position. Several parameters such as S2, HI, oil and extraction yield and fluorescent properties suggest that the Puertollano and Blanzy–Montçeau vitrains have a lower hydrocarbon potential. The relationships between geochemical and textural properties make it possible to distinguish between ‘normal' and perhydrous vitrains. The two different hydrogen-enrichment processes that occur in vitrains from the Teruel and Asturias basins can be distinguished from the extraction yield data.

Mots clés: Vitrinites; Physical properties; Chemical properties

Domaines: Géochimie

A. Jimenez, María José Iglesias, Fatima Laggoun-Défarge, Isabel Suarez-Ruiz. Study of physical and chemical properties of vitrinites. Inferences on depositional and coalification controls. Chemical Geology, 1998, 150 (3-4), pp.197-221. ⟨10.1016/S0009-2541(98)00048-5⟩. ⟨hal-00142208⟩