Amino-2-methyl-1-propanol-based Post-combustion Capture Process with Solvent Storage for Decarbonisation of Natural Gas Combined Cycle Power Plant

Abstract

Meeting the Paris Agreement targets is challenging because a high proportion of the global energy generation is based on the combustion of fossil fuels. Carbon capture and storage is expected to provide a cost-effective means of reducing CO2 emission from the fossil fuel-fired power sector. In recent times, natural gas has become the most preferred fossil fuel due to the low prices and low carbon emissions associated with its combustion in comparison to coal and other fossil fuels. Among the commonly employed carbon capture technologies, amine solvent-based post-combustion CO2 capture is known as an appropriate option for retrofitting the natural gas combined cycle (NGCC) power plants. However, the energy requirement for solvent regeneration remains a major challenge due to less electricity sold and causing an energy penalty. One way to reduce this parasitic load on the NGCC is to use alternative solvents with superior performance than the widely used monoethanolamine (MEA). Another way to address this challenge is the addition of the solvent storage system, which enables the energy penalty to be deferred until times of low electricity prices. However, investing in solvent storage will only be profitable if there is a substantial difference between the high and the low electricity prices. In this work, a process model of the NGCC with the CO2 capture plant using 2-amino-2-methyl-1-propanol (AMP) is used to evaluate the feasibility of solvent storage and its effect on economic performance. The net efficiency of the process with solvent storage was obtained to be 46.7% compared to 45.6% LHV basis for the process without solvent storage. Despite this lower efficiency, the process with solvent storage was found to increase the profit by approximately 1% compared to that without solvent storage. Thus, this would result in a higher profit than the power plant if the carbon tax exceeds €25/tCO2.