CO2 capture by activated and impregnated anthracites

Porous materials are being proposed as suitable candidates for CO2 capture due to their highly developed porous structure. Although anthracites are known to produce high surface area activated carbons, there are very limited studies on the application of activated anthracites. Accordingly, in this work, high surface area activated anthracites were prepared by steam activation and their CO2 capacities were investigated. The activated anthracites are mainly microporous. The increase in activation time results in a continuous steady rise of the mesopore area and volume, while the micropore and total pore area and volume reach a maximum at 3 h. The surface areas go through a maximum with increasing solid yields. The adsorption capacity of the activated anthracites decreases rapidly with increasing adsorption temperature, probably due to the adsorption being a physisorption process. The anthracite with the highest CO2 adsorption capacity is the sample activated at 800 °C for 2 h, whose surface area was only 540 m2/g, and the adsorbed amount of CO2 was 65.7 mg-CO2/g-adsorbent. This is probably due to a relationship between microporosity and CO2 physisorption processes. Several surface treatment methods, including NH3 heat treatment and polyethylenimine (PEI) impregnation, were used to modify the surface properties of the activated anthracites in an attempt to increase their CO2 capture capacity at higher temperatures. The surface treatment methods investigated change the porous structure and surface chemistry of the anthracites, and therefore, affect their CO2 capacities.

[1]  Y. S. Lin,et al.  Kinetics of carbon dioxide sorption on potassium-doped lithium zirconate , 2003 .

[2]  D. Cazorla-Amorós,et al.  Characterization of Activated Carbon Fibers by CO 2 Adsorption , 1996 .

[3]  J. Martín-Martínez,et al.  Microporosity development by CO2 activation of an anthracite studied by physical adsorption of gases, mercury porosimetry, and scanning electron microscopy , 1992 .

[4]  J. Martín-Martínez,et al.  Mechanisms of adsorption of CO2 in the micropores of activated anthracite , 1995 .

[5]  K. Sing.  Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Recommendations 1984) , 1985 .

[6]  J. Poston,et al.  Adsorption of CO2 on molecular sieves and activated carbon , 2001 .

[7]  J. J. Pis.  Development of macroporosity in activated carbons by effect of coal preoxidation and burn-off , 1998 .

[8]  F. Rodríguez-Reinoso,et al.  Activated carbons from lignocellulosic materials by chemical and/or physical activation: an overview , 1992 .

[9]  Chunshan Song,et al.  Chemicals and materials from coal in the 21st century , 2002 .

[10]  T. Wigmans,et al.  Industrial aspects of production and use of activated carbons , 1989 .

[11]  Chunshan Song,et al.  Environmental challenges and greenhouse gas control for fossil fuel utilization in the 21st century , 2002 .

[12]  Daniel Chinn,et al.  Amine-Grafted MCM-48 and Silica Xerogel as Superior Sorbents for Acidic Gas Removal from Natural Gas , 2003 .

[13]  M. Antal,et al.  Synthesis of a high-yield activated carbon by oxygen gasification of macadamia nut shell charcoal in hot, liquid water , 2000 .

[14]  A. Dalai,et al.  Activation of Canadian coals in a fixed-bed reactor and an internally stirred horizontal kiln , 1996 .

[15]  J. J. Pis,et al.  Preparation of active carbons from coal: Part III: Activation of char , 1998 .

[16]  J. Fierro,et al.  Study of chemical activation process of a lignocellulosic material with KOH by XPS and XRD , 2003 .

[17]  D. Do,et al.  Adsorption analysis : equilibria and kinetics , 1998 .

[18]  James Wilson,et al.  Porosity studies on active carbons from anthracite , 1976 .

[19]  Robert W. Stevens,et al.  CO2 capture by amine-enriched fly ash carbon sorbents , 2004 .

[20]  J. Andresen,et al.  Comparison of high-unburned-carbon fly ashes from different combustor types and their steam activated products , 2003 .

[21]  Antoni W. Morawski,et al.  High temperature ammonia treatment of activated carbon for enhancement of CO2 adsorption , 2004 .

[22]  M. Turmuzi,et al.  Production of activated carbon from candlenut shell by CO2 activation , 2004 .

[23]  H. Schobert,et al.  Preparation and characterization of activated carbons from anthracite , 1993 .

[24]  A. Neimark,et al.  Molecular Level Models for CO2 Sorption in Nanopores , 1999 .

[25]  Bruce G. Miller,et al.  Novel Polyethylenimine-Modified Mesoporous Molecular Sieve of MCM-41 Type as High-Capacity Adsorbent for CO2 Capture , 2002 .