Impact of Improved Sorbents on the Performance of the Carbonate Looping Process

摘要: This thesis was considered with the Carbonate Looping (CL) process and in particular impact of improved sorbents on performance. A broad overview about solid state chemistry given. Crystal systems CaCO3, CaO, Ca(OH)2 CaSO4 have been presented. It shown that CaO has most dense package all substances. However, highest melting point group which indicates sintering phenomena like loss specific surface area irreversible pore mouth blockage are much more likely to happen during re-carbonation than calcination step. Impurities coal appear become a challenge for operation CL process: On one hand impurities might get enriched loop causing high circulating mass flows other phases very occur. Special emphasis should be put usage fuel containing low amounts alkali metals. As well, reducing conditions avoided calciner avoid any undesired effects resulting system CaSO4-CaSO3-CaO. Theoretical investigations CaCO3 decomposition showed majority sorbent particles calcined within seconds calciner. Low residential times rather loadings seem achievable. The literature review revealed critical response CO2 capture ability changed TGA test conditions. In this perspective lot promising approaches, special thermal pre-treatments became less promising. speculated good reported outcomes these materials, only an effect randomly beneficial chosen Own experiments under harsh synthetic products did not indicate benefits terms ability. Mechanical chemical reactivation routes were The discussed offering both reactivations at same time is SD process. Increased mechanical stability refreshed by [86]. would repeated after each third cycle leading huge additional efforts reactivation. sophisticated model optimisations could done variety targets. Optimising economics, example, require large utilities operated as hard possible. contrast, optimal efficiency reached compromise between hardness. Minimal costs calculated 20 €/t (including compression produced power plant process). calculations handling amount make-up bleed problem. Sorbent research categorised into basic, advanced materials. Basic materials common, now available limestones, thermally treated oxides tailor-made lab samples. Based it turned out neither nor had long term advantages compared performing natural sorbents. Hardness different experimental setups created confusing picture no real correlations measurements individual achieved. Basically, two reasons identified observation: First, depending attrition wear or stress dominant. According nature products, reaction completely different. Second, cyclic change properties from carbonate shell soft sintered particle. Additionally, duration appearance Ca-forms depends strongly