This paper deals with the investigation of a cryogenic plant for the recovery of propane plus compounds from natural gas. The commercially available software ASPEN Plus (R) has been used to simulate the process, and to investigate the effect of the main operating variables on the efficiency of propane plus recovery and on the energy required by the various pieces of equipment of the plant. With respect to the base case considered, the optimized plant allows to reduce the heat required up to 25%; besides, the refrigeration required can be reduced up to 60%, without significantly affecting the propane plus recovery. (C) 2010 Elsevier B.V. All rights reserved.