Open AccessCARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS
Author(s) -
David A. Green,
Brian Turk,
Jeffrey W. Portzer,
Raghubir Gupta,
William J McMichael,
Yeru Liang,
Douglas P. Harrison
Publication year - 2002
Language(s) - English
Resource type - Reports
DOI - 10.2172/810445
Subject(s) - carbonation , calcination , carbon dioxide , chemistry , potassium carbonate , carbonate , flue gas , sodium carbonate , sulfur dioxide , inorganic chemistry , chemical engineering , mineralogy , sodium , catalysis , organic chemistry , engineering
The objective of this project is to develop a simple and inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates through reaction with carbon dioxide and water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests suggested that higher temperature calcination of trona leds to reduced carbonation activity in subsequent cycles, but that calcination in dry carbon dioxide did not result in decreased activity relative to calcination in helium. Following higher temperature calcination, sodium bicarbonate (SBC) No.3 has greater activity than either coarse or fine grades of trona. Fixed bed testing of calcined SBC No.3 at 70 C confirmed that high rates of carbon dioxide absorption are possible and that the resulting product is a mixture of Wegscheider's salt and sodium carbonate. In fluidized bed testing of supported potassium carbonate, very rapid carbonation rates were observed. Activity of the support material complicated the data analysis. A milled, spherical grade of SBC appeared to be similar in attrition and abrasion characteristics to an unmilled, less regularly shaped SBC. The calcination behavior, at 107 C, for the milled and unmilled materials was also similar