Assessment of Power Generation Systems With and Without Carbon Capture on Offshore Hydrocarbon Processing Facilities

There are very few offshore hydrocarbon processing facilities in operation that have implemented combined-cycle power generation systems, and this power scheme deserves more serious consideration and adoption due to its positive effect on carbon reduction. In this study, assessment is made of power generation schemes based on gas-driven power generation system, steam-driven power generation system and combined-cycle power generation system for an example floating production, storage and offloading (FPSO) platform design, to compare the engineering design, fuel gas consumption, equipment weights, and carbon dioxide (CO₂) emissions associated to each power generation system. It is found that the combined-cycle power generation system improves energy efficiency, reduces fuel gas consumption and in turn reduces CO₂ emissions. Further, potential implementation of an offshore carbon capture system for separating CO₂ from the gas turbine flue gases using a proprietary amine absorption technology, is presented. This paper recommends integrating combined-cycle power generation scheme and post-combustion carbon capture on the gas turbine exhausts for reducing the carbon footprint of the power generation system on the facility. Carbon capture of the process waste gas incinerator exhausts can further achieve the overall facility net-zero carbon emissions target, however this aspect is not in the scope of this paper.