چكيده به لاتين
Abstract
Asphaltene precipitation and Subsequently deposition in reservoir, surface facilities and pipes can cause major problems during oil production, transportation and processing. This research is concentrated to examination of asphaltene precipitation conditions at different temperatures, and also examination of amount of asphaltene precipitation due to adding n-pentane in two Mexican crude oil by the emphasis on thermodynamic modeling of solid phase. In the first part of this research, the precipitated asphaltene is assumed to be a pure solid and for examining vapor-liquid equilibrium, Peng-Robinson and PC-SAFT equations of state were utilized. In order to improve predictions, in the next step the poly-dispesity of asphaltene is considered and to model solid phase, the solid solution theory and UNIQUAC activity coefficient model was used. For both oil samples, in the case of using UNIQUAC activity coefficient model for asphaltene phase and PC-SAFT equation of state for vapor and liquid phases, the best agreement with experimental data were obtained. Also, when asumming asphaltene precipitate as a pure solid and using Peng-Robinson equation of state for vapor and liquid phases, it provides poor prediction.
Minimum and maximum average absolute deviation percentage in calculation of the amount of asphaltene precipitation due to adding n-pantane for oil C1 were respectively 10.2616 and 1.586, and for oil Y3 were respectively 4.1457 and 1.0196.
Keywords: Asphaltene, PC-SAFT, UNIQUAC, Solid-Solution
