Product layer development during sulfation and sulfidation of uncalcined limestone particles at elevated pressures

摘要: Fluidized bed combustion or gasification allows for in-bed sulfur capture with a calcium-based sorbent such as limestone dolomite. Sorbent particle size, porosity, internal surface, and their variation during conversion have great influence on the of sorbent. The uptake SO2 H2S by five physically different limestones is discussed, typical pressurized fluidized combustor gasifier conditions:  850/950 °C, 15/20 bar. Tests were done in thermogravimetric apparatus (P-TGA), size particles was 250−300 μm. It stressed that remain uncalcined. A changing structure (CIS) model presented which reaction kinetics product layer diffusion are related to intraparticle surface reaction, instead outer unreacted shrinking core (USC)-type models. random pore used describing surfaces. Rate parameters extracted all fiv...