The electron paramagnetic resonance (EPR) technique was used to study the behavior of the asphaltenes from the Merey crude oil (ASCM), its vacuum residue (ARVM), its fractions, and trapped compounds (A₁-ASCM, A₂-ASCM, TC-ASCM, A₁-ARVM, A₂-ARVM, and TC-ARVM). Asphaltenes were precipitated from Merey heavy crude oil and its vacuum residue. The fractionation of our petroleum asphaltenes was carried out using the para-nitrophenol (PNP) method. Two fractions named A₁ and A₂ and trapped compounds were obtained. The temperature dependence of the EPR spectra was used to obtain a set of temperatures related to free radical (FR) generation and recombination. From the analysis of the EPR spectrum of the most intense signal of the vanadium, we obtain the temperature ranges of the anisotropic-to-isotropic domains, we found a nonlinear behavior of the B parameter in the temperature range studied, and we propose a functional relationship for this parameter as a function of the temperature. On the other hand, we found the temperatures for the slow-to-fast motion regime in these samples and correlated it with the mobility of the fractions.

中文翻译：

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迈瑞重质原油沥青质中的馏分和截留化合物的电子顺磁共振研究及其真空残留物

电子顺磁共振（EPR）技术用于研究Merey原油（ASCM）中的沥青质，其减压渣油（ARVM），其馏分和捕获的化合物（A ₁ -ASCM，A ₂ -ASCM， TC-ASCM，A ₁ -ARVM，A ₂ -ARVM和TC-ARVM）。沥青质从Merey重质原油及其真空残渣中沉淀出来。我们的石油沥青质的分馏是使用对硝基苯酚（PNP）方法进行的。两个分数分别为A ₁和A ₂得到了被困的化合物。EPR光谱的温度依赖性用于获得一组与自由基（FR）生成和重组相关的温度。通过分析钒的最强信号的EPR谱，我们获得了各向异性至各向同性域的温度范围，发现了所研究温度范围内B参数的非线性行为，并提出了一个该参数与温度的关系。另一方面，我们在这些样品中发现了从慢到快运动状态的温度，并将其与馏分的迁移率相关联。