Parametric Process Design and Economic Analysis of Post-Combustion CO2 Capture and Compression for Coal- and Natural Gas-Fired Power Plants

Emmanuel Adu,Y.D. Zhang,Dehua Liu,Paitoon Tontiwachwuthikul

doi:10.3390/en13102519

Abstract

For the envisaged large number of commercial-scale carbon capture and storage (CCS) projects that are to be implemented in the near future, a number of issues still need to be resolved, the most prominent being the large capital and operational costs incurred for the CO2 capture and compression process. An economic assessment of the capture and compression system based on optimal design data is important for CCS deployment. In this paper, the parametric process design approach is used to optimally design coal and natural gas monoethanolamine (MEA)-based post-combustion CO2 absorption–desorption capture (PCC) and compression plants that can be integrated into large-scale 550 MW coal-fired and 555 MW natural gas combined cycle (NGCC) power plants, respectively, for capturing CO2 from their flue gases. The study then comparatively assesses the energy performance and economic viabilities of both plants to ascertain their operational feasibilities and relative costs. The parametric processes are presented and discussed. The results indicate that, at 90% CO2 capture efficiency, for the coal PCC plant, with 13.5 mol.% CO2 in the inlet flue gas, at an optimum liquid/gas ratio of 2.87 kg/kg and CO2 lean loading of 0.2082 mol CO2/mol MEA, the CO2 avoidance cost is about $72/tCO2, and, for the NGCC PCC plant, with 4.04 mol.% CO2 in the inlet flue gas, at an optimum liquid/gas ratio of 0.98 kg/kg and CO2 lean loading of 0.2307 mol CO2/mol MEA, the CO2 avoidance cost is about $94/tCO2.

Highlights

The global increase in energy demand and the massive industrialization drive as a result of economic and demographic growth continue to increase the amount of greenhouse gas (GHG) emissions into the atmosphere
The direct-contact cooler (DCC) cooled and conditioned the flue gas (FG) pressure, temperature, and moisture content so it met the requirement of the absorption column
The temperature and, moisture content of the FG exiting the flue gas desulfurization (FGD) was reduced in the DCC, where the FG was cooled using cooling water condensed from the FG and recirculated to the top of the DCC

Summary

Introduction

The global increase in energy demand and the massive industrialization drive as a result of economic and demographic growth continue to increase the amount of greenhouse gas (GHG) emissions into the atmosphere. Coal, petroleum, and natural gas combustion processes are the main sources of CO2 emissions [5,6], and they continue to dominate the global energy mix today, accounting for about 80% of the global primary energy demand [7,8], which needs to be decarbonized. Energies 2020, 13, 2519 the really deep decarbonation required in the power and industrial sectors may include the use of less carbon-rich fuels (such as a switch from coal to natural gas), as well as improvements in energy efficiency, renewable energy usage, carbon capture and storage (CCS), and nuclear-based energy generation [9,10,11,12]. The CCS technology is considered crucial and it is currently the only technology in the wider carbon emission mitigation approaches to achieve significant CO2 emission reduction targets [13], with the post-combustion absorption–desorption capture (PCC) utilizing aqueous monoethanolamine (MEA) solvents being the most mature and industrial CO2 capture technology commercially available currently [14]

Objectives

Results

Conclusion