Carbon Capture on FPSOs

Abstract

Abstract The paper presents the development of a flue gas carbon capture solution for gas turbines on FPSOs, which is the main source of GHG emissions onboard FPSOs. It addresses the design aspects, including layout and performance, together with the execution challenges, such as construction and commissioning. Based on the technical challenges raised by low CO2 concentration gas flow treatment offshore, the overall approach has been to combine the skills and experiences of an FPSO company and a technology provider specialist. The starting point has been to evaluate the global demand in terms of power generation required onboard an FPSO, then assess the most suitable technology available with the required level of maturity to meet short-term market needs. The carbon capture plant has then been sized based on a specific gas flow associated with the power demand. A moving column study was then performed to prove the overall performance of the plant. This study provided reliable tower sizing. Tower sizing has an essential role in the carbon capture plant's performance as well as a major impact on the layout. The main outcome of the development is that capturing CO2 from gas turbine flue gas is technically feasible offshore. The challenges are numerous; and the key challenge is the plant footprint, which has a direct consequence of the volume and characteristics of flue gas to treat. The feasibility study also showed that transposing onshore-based CO2 abatement technologies offshore is feasible. In addition, being offshore can also bring some advantages, like access to large volumes of cold water and, in some specific cases, access to CO2 reinjection capabilities. The constraints of having very large equipment on a limited area will probably drive the design by adjusting the capacity of the plant; this is a way of approaching the size of a plant that is not common in the onshore petrochemical industry. Finally, construction and commissioning will strongly influence the execution model due to the size of the plant and the utility requirements. In summary, the study demonstrates the technical feasibility of significantly reducing CO2 emissions from FPSO operations offshore.