An experimental investigation of alkali removal from biomass producer gas using a fixed bed sf solid sorbent

A bench-scale gasifier system composed of a fluidized-bed gasifier, high-te mperature ceramic filter, and fixed-bed solid sorbent reactor was used to s tudy the removal of alkali from a hot product gas stream. During a test con ducted with an empty solid sorbent reactor, dry gas-phase concentrations of 28 ppmw K, 11 ppmw Na, and 1309 ppmw Cl were measured. Four subsequent tes ts utilized 2.4-3.4-mm-diameter particles of activated bauxite or emathlite in the solid sorbent reactor. Over these four tests, Ii concentrations ran ged from 0.03 to 0.07 ppmw, and Na concentrations ranged from 0.2 and 0.9 p pmw at the exit of the solid sorbent reactor. Chlorine concentrations at th e exit of the reactor were essentially unaffected, Hot-water leaching tests indicated that alkali capture by activated bauxite and emathlite was throu gh physical adsorption and chemisorption, respectively.