Determinação de dados de equilíbrio de fases a altas pressões para o sistema sintético dióxido de carbono e esqualano

• Autor(a) principal: Araújo, Izabella Regina de Souza
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/38819
• topic: Equilíbrio líquido-vapor; Altas pressões; Método sintético; Sistema binário; Dióxido de carbono; Esqualano; Vapor-liquid equilibrium; High pressure; Synthetic method; Binary system; Carbon dioxide; Squalane; Engenharias.

This work aimed to investigate the vapor-liquid equilibrium for the binary system carbon dioxide and squalane at high pressures and moderate temperatures. The vapor-liquid equilibrium was studied through experiments performed in an equilibrium cell to determine bubble pressure using both visual and non-visual synthetic methods with phase change. The experiments were conducted at moderate temperatures ranging from 30 to 120 °C, and at high pressures, from 55 to 197 bar. The CO2 molar fraction ranged from 47 to 80%. 175 bubble points were obtained as results through visual synthetic method, with measurements of pressure, temperature and liquid phase composition. These data were entered in the Software Specs v5.63, using SRK equation of state, the Mathias-Copeman temperature dependence, and a quadratic mixing rule to calculate the binary interaction parameters. The values of these binary interaction parameters determined by computational modeling using Specs were kij = 0.1002 ± 0.000648 and lij = 0.0135 ± 0.001078, with a mean percentage error for experimental bubble pressure in comparison to calculated bubble pressure of 2.87%. The use of non-visual synthetic method confirmed the accuracy of the visual synthetic method. Through generation of envelope phase curves using Specs with the previously calculated parameters, it was noticeable that the model fitted the experimental data. In addition, a comparison was made between these values of kij and lij and values determined by using of literature data, and it resulted in a mean percentage error lower than 10% for binary interaction parameter kij.