  Quenched or frozen-in, structural disorder is ubiquitous in real experimental
systems. Much of the progress is achieved in understanding the phase separation
of such systems using diffusion-driven coarsening in Ising model with quenched
disorder. But there is a paucity of research in the phase-separation kinetics
in fluids with quenched disorder. In this letter, we present results from a
detailed Molecular dynamics (MD) simulation the effects of randomly placed
localized impurities on the phase separating kinetics of binary fluid mixture.
Our system resembles the fluid imbibed into a porous medium. We observe a
dramatic slowing down in the pattern formation with increasing pin particle
concentration. The domain growth follows the power-law with a
disorder-dependent exponent. Due to the energetically favorable positions, the
domain boundary roughens which modifies the correlation function and structure
factor to a non-Porod behavior. The correlation function and structure factor
provide clear evidence that the superuniversality does not hold in our system.
