Limestone and dolomite as sulfur absorbents under pressurized gasification conditions

摘要: Abstract The capture of H2S by both limestone and dolomite was studied with a pressurized thermogravimetric apparatus. experimental conditions were chosen to correspond the typical in fluidized bed gasifier. Depending on these reacts either uncalcined (CaCO3) or calcined (CaO), half-calcined (CaCO3 + MgO) fully (CaO MgO), H2S. reaction product is calcium sulfide (CaS). MgO does not react under circumstances, due thermodynamic limitations. absorption capacities three dolomites two limestones particle size 125–180 μm compared at 950°C 2 MPa. fast 80–90 wt% Ca converted CaS. slow after h no more than 20 had reacted Half-calcined significantly efficient 60–80 CaS within 60 min. Experiments also carried out lower temperatures. For rate still too for kinetic studies 750°C. However, clearly decreased observed activation energy ∼ 100 kJ mol−1 300–400 mol−1.