Cyclic Use of Calcined Dolomite to Desulfurize Fuels Undergoing Gasification

Capture of CO2 from combustion gases in a fluidized bed of CaO

“…However, this technology introduces severe efficiency penalties and added costs (Rao and Rubin, 2002), and this justifies a range of emerging approaches that claim to be more energy efficient and costeffective than low-temperature absorption-based systems. One of these approaches (Silaban and Harrison, 1995) involves the separation of CO 2 at high-temperatures (Ͼ600°C) using the carbonation reaction of CaO CaO ͑s͒ ϩ CO 2 ͑g͒ 3 CaCO 3 ͑s͒ T between 650°C-850°C depending on pressure (1) The background for this separation process dates back to 1867, when DuMotay and Marechal first patented the use of lime to aid the gasification of carbon by steam (Squires, 1967). The carbonation reaction can take place in a reducing atmosphere to enhance H 2 formation (Lopez-Ortiz and Harrison, 2002;Ziock et al, 2002;Lin et al, 2002;Areklett and Nygaard, 2002;Bandi et al, 2002;Wang et al, 2004), or in a combustion flue gas (Shimizu et al, 1999;Griffin et al, 2003;Wang et al, 2004).…”

Chemical Looping Particles

“…It was fi rst introduced by DuMotay and Marechal in 1869 for enhancing the gasifi cation of coal 75 and followed by CONSOL ' s CO 2 Acceptor process 76 a century later when this concept was tested in a 40 -t/d plant. A variation of this process, the HyPrRing Process, 77,78 was developed in Japan for the production of hydrogen at high pressures.…”

what's new in high temperature sulfur removal systems for fluidized-bed coal gasification

“…This problem may be overcome by carrying out the reaction at pressure. 13 Pell's 14 early work, however, showed that CaS is rapidly deactivated; and TG studies show that only 20% of the CaS is readily converted to CaCO3 after 10 cycles of sulfidation/regeneration, at 704°C.…”