Simulation and analysis of SCORE propane recovery process

SCORE (Single Column Overhead Recycle) process is a cryogenic-separation process which is widely used abroad and mainly for recovery of propane and heavier compositions in natural gas. SCORE process is improved from OHR (Overhead Recycle) process, and it has characteristics of simple flow, high propane recovery, well integrated system, strong adaptability for natural gas with different richness. The SCORE process structure, principles and characteristics are analyzed in this article. Composite column consisting of absorbing section and stripping section has been adopted in SCORE process. A with-drawn gas flow is cooled and its condensate for reflux of absorbing section and feed of with-drawn gas flow. The feed gas is cooled by cryogenic with-drawn liquid flow which results in lower reboiler energy consumption, better integration of system and higher propane recovery. Effects of operating conditions such as column overhead reflux, with-drawn gas and liquid flow on SCORE process propane recovery and system energy consumption are analyzed in this article by actual cases. Three sets of natural gases with different richness are selected to study SCORE process adaptability, and the results show that SCORE process is an efficient recovery process with high propane recovery and wide range of adaptability. And it is worthy of promotion in propane recovery engineering field in our country.