The FCMOM (finite size domain complete set of trial functions method of moments) is an efficient and
accurate numerical technique to solve monovariate and bivariate population balance equations. It was previously
formulated for homogeneous systems. In this paper, the FCMOM approach is extended to solve monovariate
population balance equations for inhomogeneous (spatially not uniform) systems. In the FCMOM, the method
of moments is formulated in a finite domain of the internal coordinates and the particle size distribution
function is represented as a truncated series expansion by a complete system of orthonormal functions. The
FCMOM is extended to inhomogeneous systems assuming that the particle-phase convective velocity is
independent of the internal variables (particle size). The method is illustrated by applications to particle diffusion
and to particle convection. In the case of particle convection, a gas-solid dilute flow in a pipe was simulated
and the FCMOM equations were coupled with the governing equations (mass and momentum balances) of
the gas phase
