Apparatus for condensing hydrocarbons, such as but not limited to butane and propane, from a stream of natural gas includes as its primary components a pre-cooler assembly, a chiller assembly, a refrigerant compressor/condenser assembly, and separator assembly. In the pre-cooler assembly warm gas entering the apparatus is cooled by counter-current flow heat exchange with cooled natural gas exiting the apparatus. The chiller assembly of the apparatus the hydrocarbon stream is cooled in co-current flow heat exchange with a first refrigerant tube, carrying a first refrigerant which is itself cooled in co-current heat exchange with a second refrigerant tube disposed in coaxial relationship with the first refrigerant tube. Both first and second refrigerant tubes are disposed in coaxial relationship with an outer jacket conveying the gas stream through the chiller assembly. Condensed hydrocarbons are separated from the gas stream in the separator assembly.