Synergies Between Membrane Pretreatment and NGL Recovery in an Offshore Environment

Abstract

Abstract Interest has been piqued in the use of membranes for the removal of bulk carbon dioxide from natural gas in an off-shore environment because of the advantages that membranes present in weight, space efficiency and tolerance of motion. Integration on the membrane unit into the platform provides opportunities for synergies between hydrocarbon dewpointing membrane pretreatment and natural gas liquids recovery. Optimization of the hydrocarbon dewpoint pretreatment provides tradeoffs between capital expense, operating expense, weight and natural gas liquids recovery while meeting the membrane hydrocarbon dewpoint requirement. There is an opportunity for the Owner and EPC contractor to define hydrocarbon dewpointing configuration and operating setpoints to maximize the return on investment while meeting the membrane vendor's requirements for dewpointing. Where these opportunities have been identified, direction should be provided by the project to the membrane vendor, whose focus is on the hydrocarbon dewpointing requirements and may not intimately understand all of project objectives including synergies with natural gas liquids recovery. Introduction Gas is becoming an increasingly important part of the global energy equation constituting 20.3% of the energy mix in 2010 which is expected to further increase to 24.7% of the mix by 2035 per WEO-2012 (2012) [Fig. 1].