  The appropriate design, construction, and operation of carbon capture and
storage (CCS) and enhanced oil recovery (EOR) processes require a deep
understanding of the resulting phases behavior in hydrocarbons-CO_2
multi-component mixtures under reservoir conditions. To model this behavior a
nonlinear system consists of the equation of states and some mixing rules (for
each component) needed to be solved simultaneously. The mixing usually requires
to model the binary interaction between the components of the mixture. This
work employs optimization techniques to enhance the predictions of such model
by optimizing the binary interaction parameters. The results show that the
optimized parameters, although obtained mathematically, are in physical ranges
and can reproduce successfully the experimental observations, specially for the
multi-component hydrocarbons systems containing Carbon dioxide at reservoir
temperatures and pressures
