In the present study, the power consumption in a stirred vessel by two-blade impeller has been investigated. 3D finite volume based computational fluid dynamics (CFD) simulations have been carried out. The tank used has a cylindrical shape with a flat bottom. The liquid height was kept equal to the vessel diameter. Study has been restricted to the laminar regime with Newtonian and shear thinning fluids, which are typical conditions of polymerization reactions. Analyses concern the effect of the impeller speed, the fluid rheology and some design parameters on the power consumption and a new correlation is proposed. Predictions have been compared with literature data and a satisfactory agreement has been found. (C) 2012 Elsevier Ltd. All rights reserved.