Circulating fluidized beds (CFB) find a wide-spread application in a variety of industrial processes such as coal combustion and coal gasification, catalytic cracking of oil, and gas purification. A one-dimensional model is developed to characterize the pressure drop partitions among solids concentration, solids acceleration, and energy loss in the acceleration zone in a CFB riser. The axial distributions of solid velocity and solid concentration are obtained by solving the equations. Consequently effects of solids acceleration and energy loss on the axial distributions of solids velocity and concentration are presented. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).