A newly developed hybrid solution algorithm applicable on turbulent multiphase, gas-solid, reactive flows is presented. A finite volume (FV) and a probability density function (PDF) method are combined. The FV technique is used to solve the total mass and momentum conservation equations together with the k-epsilon turbulence equation for the gas phase and the granular temperature equation for the solid phase. The PDF method is applied to solve the species continuity equations and avoids the need to model the chemical source terms in the latter. Stochastic differential equations (SDEs) are introduced as replicas of the transported composition PDF equations. The notional-particle-based Monte-Carlo technique is used to solve the PDF model equations. The hybrid FV/PDF solution algorithm is applied to simulate a fluid catalytic cracking (FCC) riser using a 12-lump kinetic model. A good agreement between simulated results and available plant data is obtained. (C) 2011 American Institute of Chemical Engineers AIChE J, 58: 268-284, 2012