In this paper, we study a partial exclusion process in random environment, where the random environment is obtained by assigning a maximal occupancy to each site. This maximal occupancy is allowed to randomly vary among sites, and partial exclusion occurs. Under the assumption of ergodicity under translation and uniform ellipticity of the environment, we prove the quenched hydrodynamic limit. To this purpose, we exploit the self-duality property of the interacting particle system to transfer, via a mild solution representation of the empirical density fields and the tightness criterion developed in [35], a homogenization result concerning random walks in the same environment with arbitrary starting points to the particle system.