The influence of the catalyst precursor anion in catalysis of water vapour gasification of carbon by potassium

摘要: Based on a fundamental clarification of the activity various potassium salts as precursors for catalysed water vapour gasification in part 1 this paper, catalytic was studied by experiments fixed bed flow reactor using equimolar argon/water and hydrogen/water mixtures. The activities found with (hydroxide, carbonate, nitrate, sulphate, chloride) characterized onset maximum rates during linear heating (4 K min −1), were to be identical kinetics activation, confirming following sequence: KOH ~ K2CO3 KNO3 >K2SO4 >KCl. As hydroxide represents key component activation all salts, active species has formed from compound. is defined non-stoichiometric potassium-oxygen compound KxOy (y < x) varying oxygen contents. It acts dissociation centre transfers carbon surface, which monoxide finally desorbed. A high selectivity towards dioxide methane are explained shift reaction methanation primary being actual different content. Deactivation sulphur does not occur. There also strong irreversible deactivation silicates. Inhibition hydrogen interpreted blocking sites at surface.