Exploration on process design, optimization and reliability verification for natural gas deacidizing column applied to offshore field

Onshore acid gas purification technology and experience are extended to offshore situation in this paper. Deacidizing technique using mixed amine solvent of methyldiethanolamine (MDEA) and diethanolamine (DEA) is researched and applied into a specific offshore gas field. The process is simulated and analyzed according to the parameter design and type selection of column which is the most important equipment on decks. Furthermore, the ranges of key parameters are proposed. Different process schemes are analyzed comprehensively and the optimum parameters are selected using the method of Five Factors Fuzzy Industrial Evaluation for Column Capability. The structure design of absorption column is also performed. Stress and strain changes are studied under different tilt angles and working conditions by ANSYS software. The reliability of column structure design is verified and the process solution for the specific gas field is optimized. The research can provide certain guidance and reference to natural gas deacidizing technology for offshore field.

► Process selection and column design are in view of offshore conditions.
► Using method of Five Factors Fuzzy Industrial Evaluation for Columns Capability.
► Reliability is verified by modeling of column under various sea conditions.
► An optimized process scheme is achieved and key parameters are determined.