The object of this study is to investigate the question of convective movement of a reacting solute in a viscous incompressible occupying a plane layer in a saturated bidisperse porous material. Among the characteristics of a bidisperse porous medium are pores, called macropores, but porosity in the solid skeleton, known as microporosity, arises where there are cracks or fissures in that skeleton. In this paper, a comparison is made between the thresholds for linear instability and those obtained from a global nonlinear energy stability analysis.