Solvatochromic and Solubility Parameters of Solvents: Equivalence of the Scales and Application to Probe the Solubilization of Asphaltenes

Autor(es)

Novaki, Luzia P. ^[1] ; Moraes, Edgar O. ^[1] ; Goncalves, Andre B. ^[1] ; de Lira, Raphael A. ^[1] ; Linhares, Vanessa N. ^[1] ; de Oliveira, Marcia C. K. ^[2] ; Meireles, Francis A. ^[2] ; Gonzalez, Gaspar ^[3] ; El Seoud, Omar A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem, SP POB 26077, BR-05513970 Sao Paulo, SP - Brazil

^[2] Petrobras Res Ctr CENPES, Flow Assurance Lab, Ave Horacio Macedo 950, Cidade Univ, BR-21941915 Rio De Janeiro, RJ - Brazil

^[3] Univ Fed Rio de Janeiro, Inst Macromol, Ave Horacio Macedo 950, Cidade Univ, BR-21941915 Rio De Janeiro, RJ - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENERGY & FUELS; v. 30, n. 6, p. 4644-4652, JUN 2016.
• Citações Web of Science: 6

Resumo

The oil compatibility model is important for assessing the stability of crudes. The compatibility between maltenes and the corresponding asphaltenes, Asphs, can be assessed from the solubility parameters (Hildebrand and Hansen) of both components of the crude. Solvatochromism is the effect of the medium on the UV/vis spectra of substances (solvatochromic probes) that are sensitive to the properties of the medium, namely, its empirical (or overall) polarity, Lewis acidity and basicity, dipolarity, and polarizability. Therefore, the solubility and solvatochromic parameters of solvents should be related. We synthesized a novel solvatochromic probe (E-2,6-di-tert,butyl-4-(2-(1-hexylquinolin-1-ium-4-yl)vinyl)phenolate, HxQMBu(2)) whose properties are convenient to study in nonpolar and polar solvents. The empirical solvent polarities measured with HxQMBu2 in 38 solvents correlated linearly with the corresponding Hildebrand solubility parameters. Likewise, the solvent Lewis acidity/basicity, dipolarity, and polarizability correlated linearly with the corresponding Hansen solubility parameters. To test the equivalence of the two scales (solvatochromic and solubility parameters), we determined the solubility of Asphs in 28 solvents, pertaining to different chemical classes. The dependence of Asph solubility on three solvent descriptors (Lewis acidity/basicity, dipolarity, and polarizability) was tested. Our results indicated that alcohols and hydrocarbons are inefficient solvents; solvents of intermediate efficiency carry either a strongly dipolar group or polarized bonds. Aromatic and heterocyclic solvents are most efficient. The most relevant solvent descriptor (for the dissolution of Asphs) is ifs polarizability. (AU)

• Processo FAPESP: 14/22136-4 - Uso de solventes verdes e suas misturas na otimização de processos químicos
• Beneficiário: Omar Abou El Seoud
• Modalidade de apoio: Auxílio à Pesquisa - Temático