High pressure phase equilibria of multicomponent systems containing alcohols, water and carbon dioxide

Abstract

High pressure vapor-liquid equilibria for the binary carbon dioxide + 2-pentanol, carbon dioxide + 3-pentanol, carbon dioxide + 2-methyl-1-butanol, carbon dioxide + 2-methyl-2-butanol, carbon dioxide + 3-methyl-1-butanol, and carbon dioxide + 3-methyl-2-butanol systems were newly measured at 313.2 K. The phase equilibrium apparatus used in this work is of the circulation type in which the coexisting phases are recirculated, on-line sampled, and analyzed. The phase equilibria for the ternary carbon dioxide + water + 2-pentanol, carbon dioxide + water + 3-pentanol, carbon dioxide + water + 2-methyl-1-butanol, carbon dioxide + water + 2-methyl-2-butanol, carbon dioxide + water + 3-methyl-1-butanol, carbon dioxide + water + 3-methyl-2-butanol, and carbon dioxide + methanol + 2-methyl-2-butanol systems were also measured at 312.1 K and at pressures of 20, 40, 60, 80, and the critical points of each system. In particular, fine control of pressure needed to measure the highly accurate critical point was obtained by using a pressure generator. The ternary carbon dioxide + water + 2-pentanol, carbon dioxide + water + 3-pentanol, carbon dioxide + water + 2-methyl-1-butanol, carbon dioxide + water + 2-methyl-2-butanol, carbon dioxide + water + 3-methyl-1-butanol, carbon dioxide + water + 3-methyl-2-butanol systems showed three LLV phases for the range of pressure up to the critical point of each systems. Only the carbon dioxide + methanol + 2-methyl-2-butanol ternary system showed binary phase through all pressure investigated. The binary experimental data were correlated with the Redlich-Kwong, Soave-Redlich-Kwong, Peng-Robinsons, and Patel Teja equations of state with two different mixing rules; the van der Waals mixing rule with one binary interaction parameter, Panagiotopoulos-Reid mixing rule with two binary interaction parameters. The six Huron-Vidal type mixing rules were tested to the above all binary system and compared each other. The binary experimental data wa...