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Investigations of the Conversion of Inorganic Carbonates to Methane
Author(s) -
Jagadeesan Dinesh,
Eswaramoorthy Muthusamy,
Rao C. N. R.
Publication year - 2009
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.200900152
Subject(s) - methanation , catalysis , methane , transition metal , carbon fibers , thermal decomposition , chemistry , decomposition , inorganic chemistry , oxide , substitute natural gas , metal , selectivity , yield (engineering) , carbonate , materials science , chemical engineering , syngas , metallurgy , organic chemistry , composite number , engineering , composite material
Inorganic carbonates, which occur abundantly on earth, constitute an inexpensive natural source of carbon. Therefore, the direct conversion of these carbonates into methane is of considerable importance. Thermal decomposition of transition metal carbonates with the composition MCa(CO 3 ) 2 (where M=Co, Ni, or Fe, and M/Ca is 1:1) and M 1 M 2 Ca(CO 3 ) 3 (where M 1 M 2 =CoNi, NiFe, or FeCo, and M 1 /M 2 /Ca is 1:1:2) shows that the reduced transition metals in combination with metal oxide nanoparticles (e.g., Co/CoO/CaO) act as catalysts for the conversion of CO 2 (produced from the carbonates) into methane. The favorable decomposition conditions include heating at 550 °C in an H 2 atmosphere for 5–6 h. These catalysts are found to be excellent for the methanation of CaCO 3 , exhibiting high efficiency in the utilization of H 2 with 100 % conversion and 100 % selectivity. The best catalyst for conversion of CaCO 3 into CH 4 is Co/CoO/CaO. There are also indications that similar catalysts based on Fe may yield higher hydrocarbons.