Challenge and Continuity

Monodisperse Thermodynamic Model Based on Chemical + Flory–Hüggins Polymer Solution Theories for Predicting Asphaltene Precipitation

“…2. It was confirmed that the traditional models based on the Flory−Huggins 24,25,109 polymer solution theory, 4,5,11,27,71 which assume that either the precipitated phase consists of asphaltene only or the precipitated phase consists of asphaltene and nonasphaltene components and the oil phase is free of asphaltene (due to lower concentration of asphaltene than maltene concentration), may not be helpful for the conditions where χ is near 0.5 and may require some modifications. 1 3.…”

“…A thermodynamic model based on the chemical theory of associated solutions with physical interactions, 25,107,108 in which it is assumed that asphaltene forms a pseudocomponent and the precipitated and nonprecipitated phases contain asphaltene and nonasphaltene components was then introduced. The study shows that the existing traditional Flory−Huggins 4,5,11,27,71 based models could be specific cases of the developed model. 4.…”

“…23 Asphaltene precipitation can cause severe difficulties during oil production, transportation, and processing as follows: fouling in the reservoirs, wettability alterations, flow blockage with excess pressure drop in wellbore tubings, surface pipelines, and upstream process facilities, as well as poisoning of refinery catalysis. [1][2][3][4][5][6][7][8]11,15 As the oil pressure drops during production above the bubble point of some crudes oils, especially those containing high fractions of saturates, asphaltenes may precipitate. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]20,21 During enhanced oil recovery when compressed gases, such as methane (or natural gas) or carbon dioxide, are injected into the reservoir, asphaltenes may also precipitate because it alters the reservoir fluid.…”

“…[1][2][3][4][5][6][7][8]11,15 As the oil pressure drops during production above the bubble point of some crudes oils, especially those containing high fractions of saturates, asphaltenes may precipitate. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]20,21 During enhanced oil recovery when compressed gases, such as methane (or natural gas) or carbon dioxide, are injected into the reservoir, asphaltenes may also precipitate because it alters the reservoir fluid. 1,7,8,11 Once crude oils are brought to the surface, they are commonly mixed in the field, in tankers, and/or pipelines.…”

Expanding the Structural Diversity at the Phenylene Core of Ligands for the von Hippel-Lindau (VHL) E3 Ubiquitin Ligase: Development of Highly Potent Hypoxia-Inducible Factor-1alpha (HIF-1alpha) Stabilizers

“…hydroxylated HIF-1α, and its molecular recognition by VHL as a starting point. [14][15][16] The first co-crystal structure (PDB 1LM8) of a 20-residue HIF-1α peptide bound to the VHL-EloC-EloB complex (VCB) showed HIF-1α in an extended β strand-like conformation. Hydroxyproline Hyp564, which originated from post-translational hydroxylation, was inserted into a groove in a hydrophobic core formed by buried, mostly aromatic residues.…”