Offshore CO2 Capture from gas turbine with low investment optimized using Aspen HYSYS

Abstract

CO₂ capture from gas turbine exhaust gas is a possibility for CO₂ emission reduction on oil and gas production platforms. A standard process is based on absorption in monoethanol amine (MEA). A challenge is that the cost of size and weight for the process equipment is higher than on a land-based process. A standard process based on CO₂ absorption into (MEA) is simulated in Aspen HYSYS^TM. The equipment cost was obtained from Aspen In-plant Cost Estimator^TM. The base case is based on assumptions which are in earlier works assumed to be close to optimum for a land-based process with a heat consumption of 3.5 MJ/kg removed CO₂. Different parameters as the number of stages in the absorption column and the minimum temperature approach are varied in the direction expected to be more optimum for an offshore application. It is expected that a lower absorption column and smaller heat exchangers are more optimum offshore even though the heat consumption will increase. Parametric studies were performed at 90 % capture efficiency. Suggested conditions for an offshore application with 87 % capture efficiency are 13 m absorber packing height and 15°C minimum approach temperature due to a decrease in equipment cost, size and weight. This is expected to balance the increase of heat consumption to approximately 5.5 MJ/kg CO₂ removed.