Recent studies have shown that a high K dielectric solvent screens the impurities for room temperature transport in graphene and the mobility has been found to increase by orders of magnitude. This gives what is probably the intrinsic, phonon limited mobility at room temperature, and we have confirmed this with simulation. Mobility as high as 44 000 cm(2) V(-1) s(-1) was achieved. At very low density, impurity scattering still is the determining factor for mobility, but this is significantly reduced in the recent experiments due to the dielectric screening. At high density, impurity scattering becomes negligible.