Compression refrigeration is widely used in chemical processes to cool process streams to below-ambient temperatures. A single stage (one evaporator, one compressor, one condenser and one expansion valve) can be used down to temperatures of about -40 degrees C using several refrigerants such as R134A, ammonia and propylene. Lower temperatures require multiple stages using progressively lower-boiling refrigerants in each stage. The selection of the "best" refrigerant involves economic, environmental, safety and political issues as well at technical performance and economics. The Freon refrigerants are safe but impact the ozone layer. Ammonia and propylene present safety concerns due to toxicity and flammability. The purpose of this paper is to explore how the desired temperature of refrigeration affects the refrigerant selection and the number of stages with only economic monetary considerations taken into account. The economic objective function considers both compressor energy costs and capital investment in compressors and heat exchangers. (C) 2019 Elsevier Ltd. All rights reserved.