Solvent Swelling Studies of Green River Kerogen

Kinetics of oil group-type generation and expulsion: An integrated application to Dongying Depression, Bohai Bay Basin, China

“…Volumetric solvent swelling is a method that has been widely used to characterize solvent-kerogen interaction and the macromolecular structure of various kerogens (Larsen and Li, 1994;Larsen and Li, 1997a,b;Ballice, 2003;Ballice and Larsen, 2003). The solubility of a compound in a polymer can be defined by a solubility parameter, d, which is frequently referred to as the Hildebrand parameter (Hildebrand, 1936).…”

Examination of molecular weight distributions of primary pyrolysis oils from three different oil shales via direct pyrolysis Field Ionization Spectrometry

“…Based on the three oil shales studied, it could be from 350 to 600 daltons. Table 2 Indicative values of the calculated number average molecular weights per cross-links for different oil shale kerogens published in the literature (Green River [35], Göynük [37], Beypazari [37], Dictyonema [38], Kukersite [39] …”

“…If the molecular weight distribution from py-FIMS is viewed to represent the size distribution of structural units (so called monomers) that form larger structures (so called oligomers) between cross-links, it is plausible to assume that the average molecular weight between cross-links should not be smaller than about 350-450 daltons. Therefore, at least the FloryRehner model clearly underestimates the average molecular weights between cross-links, and does so even for Green River kerogen, which is expected to follow Regular Solution Theory reasonably well [35] -suggesting that the reason for underestimation could be partly related to an elastic term of the classical FloryRehner theory. On the other hand, in light of the fact that the ''average repeating structural unit'' of the oil shale kerogens could consists of a 2-3 ring hydro-aromatic/aromatic cluster with a significant number of short attachments and a long roughly linear alkyl-chain [33,36], it is also not easy to interpret the estimates of the Kovac model, which expects the existence of ''rigid'' clusters (condensed aromatic structures with 3-5 rings) with a molecular weight much larger than that of the connecting short flexible links or bonds [34].…”

“…On the other hand, some oil shale solvent swelling studies have semi-quantitatively evaluated the average molecular weight between cross-links (or cross-link density) by applying swelling models related to Regular Solution Theory, such as the FloryRehner and Kovac models [34,35]. Note that the average molecular weight between cross-links is an input parameter for the structure of coal in the FG-DVC model, determined from experimental swelling data using simple swelling models -models based on Regular Solution Theory [14].…”

Application of DSC to study the promoting effect of a small amount of high donor number solvent on the solvent swelling of kerogen with non-covalent cross-links in non-polar solvents

“…Therefore, differences in trends and characteristics of swelling behavior can be found in the literature. For example, Larsen and Li [9,10] showed that less polar Green River oil shale kerogen follows regular solution theory reasonably well, while more polar Rundle kerogen shows significant deviations from such behavior, presumably because of specific kerogen-solvent interactions. The latter behavior is also characteristic of Estonian oil shales -Kukersite [11,12] and Dictyonema [13,14] -which have organic matter with a high O/C ratio (0.1-0.2).…”