CO2 capture from coal-fired power plants based on sodium carbonate slurry; a systems feasibility and sensitivity study

Abstract In this work the feasibility of a CO2 capture system based on sodium carbonate–bicarbonate slurry and its integration with a power plant is studied. The results are compared to monoethanolamine (MEA)-based capture systems. Condensing power plant and combined heat and power plant with CO2 capture is modelled to study the feasibility of combined heat and power plant for CO2 capture. Environmental friendly sodium carbonate would be an interesting chemical for CO2 capture. Sodium carbonate absorbs CO2 forming sodium bicarbonate. The low solubility of sodium bicarbonate is a weak point for the sodium carbonate based liquid systems since it limits the total concentration of carbonate. In this study the formation of solid bicarbonate is allowed, thus forming slurry, which can increase the capacity of the solvent. With this the energy requirement of stripping of the solvent could potentially be around 3.22 MJ/kg of captured CO2 which is significantly lower than with MEA based systems which typically have energy consumption around 3.8 MJ/kg of captured CO2. Combined heat and power plants seem to be attractive for CO2 capture because of the high total energy efficiency of the plants. In a condensing power plant the CO2 capture decreases directly the electricity production whereas in a combined heat and power plant the loss can be divided between district heat and electricity according to demand.

[1]  P. V. Danckwerts,et al.  Fast reactions of CO2 in alkaline solutions— (a) Carbonate buffers with arsenite, formaldehyde and hypochlorite as catalysts (b) Aqueous monoisopropanolamine (1-amino-2-propanol) solutions , 1963 .

[2]  George Skodras,et al.  Energy and capital cost analysis of CO2 capture in coal IGCC processes via gas separation membranes , 2004 .

[3]  Umberto Desideri,et al.  Performance modelling of a carbon dioxide removal system for power plants , 1999 .

[5]  A. Hill,et al.  AQUEOUS SOLUBILITY OF SALTS AT HIGH TEMPERATURES. I. SOLUBILITY OF SODIUM CARBONATE FROM 50 TO 348°1 , 1932 .

[6]  G. Witkamp,et al.  Solid Phases and Their Solubilities in the System Na2CO3 + NaHCO3 + Ethylene Glycol + Water from (50 to 90) °C , 2004 .

[7]  K. Kobe,et al.  Thermochemistry of Sodium Carbonate and Its Solutions , 1948 .

[8]  Gary T. Rochelle,et al.  Carbon dioxide absorption with aqueous potassium carbonate promoted by piperazine , 2004 .

[9]  Risto Lahdelma,et al.  CO2 emissions trading planning in combined heat and power production via multi-period stochastic optimization , 2007, Eur. J. Oper. Res..

[10]  D. Savage,et al.  Carbon dioxide absorption into promoted carbonate solutions , 1988 .

[11]  Edward S. Rubin,et al.  Identifying Cost-Effective CO2 Control Levels for Amine-Based CO2 Capture Systems , 2006 .

[12]  Olav Bolland,et al.  A novel methodology for comparing CO2 capture options for natural gas-fired combined cycle plants , 2003 .

[13]  A. Hill,et al.  Aqueous Solubility of Salts at High Temperatures. II. The Ternary System Na2CO3—NaHCO3—H2O from 100 to 200° , 1934 .

[14]  Umberto Desideri,et al.  CO2 capture in small size cogeneration plants: technical and economical considerations , 1998 .

[15]  V. V. Mahajani,et al.  The stripping of CO2 from amine-promoted potash solutions at 100°C , 1983 .

[16]  B. Dodge,et al.  Rate of Carbon Dioxide Absorption by Carbonate Solutions in a Packed Tower , 1937 .

[17]  G. Astarita,et al.  Promotion of CO2 mass transfer in carbonate solutions , 1981 .

[18]  E. Rubin,et al.  Sorbent Cost and Performance in CO2 Capture Systems , 2004 .

[19]  A. Hill,et al.  TERNARY SYSTEMS. VI. SODIUM CARBONATE, SODIUM BICARBONATE AND WATER , 1927 .

[20]  E. Baker,et al.  Absorption of Carbon Dioxide in Sodium Carbonate-Bicarbonate Solutions , 1933 .

[21]  Douglas P. Harrison,et al.  Carbon Dioxide Capture Using Dry Sodium-Based Sorbents , 2004 .