Liquid-liquid phase equilibria in the four-component system morpholine-monoethanolamine (MEA)-benzene-n-hexane at temperatures of 40, 50, and 60degreesC and MEA content in morpholine of 50-100 wt. % are described by a full third-degree polynomial. These equations tire used for modeling extraction (multistage countercurrent according to a scheme with recycling) of aromatic hydrocarbons mixed with nonaromatic hydrocarbons. Equations are obtained that correlate the degree of extraction and purity of the extract with the fundamental factors of the process. The process is optimized. The results showed the superiority of the extraction properties of the binary extracting agents investigated over glycols. The use of these extracting agents in production of aromatic hydrocarbons reduces operating expenses.