Evaluación de aceite de Jatropha gossypiifolia como estabilizante de asfaltenos en una muestra de petróleo a nivel de laboratorio

Abstract

Asphaltenes are condensed polyaromatic solids that are present in oil forming colloidal suspensions in a thermodynamic system that in some cases tends to be unstable producing flocculation and aggregation. In the oil industry, dispersant chemical compounds are used to minimize the flocculation of asphaltenes to avoid clogging problems in pipes and production equipment, which represent an important investment since they are formulated with synthetic resins and oils, in addition to expensive solvents. This research evaluates the use of Jatropha gossypifolia oil as an active stabilizing component of asphaltenes, mixed with diesel as a solvent in laboratory level tests. Five dilutions of oil in diesel (10 to 50%) were evaluated. The procedure consisted of observing the asphaltene aggregates under an optical microscope when applying n-heptane to a crude oil sample from Monagas State, Venezuela, the volume of n-heptane used being the flocculation onset. Successive volumes of each dilution were then applied until the dispersion of the aggregates was achieved, being this volume the point of dispersion. In addition, xylene was used as a standard dispersant to compare the performance of the dissolutions. The tests were performed at two temperatures of 25 and 40 ºC. A factorial statistical design was used with experimental factors dissolution and temperature and dependent variable instability index, with ANOVA analysis and Tukey HSD test with α = 0.05. With the application of the solutions, a greater dispersion of the aggregates was achieved with efficiencies greater than 94% with respect to the dispersion obtained with xylene, being the solution with 40% oil the most efficient. The statistical results showed that stability is dependent on the solution used and independent of the test temperature with a 95% confidence level.