Four FBC bed ashes were steam hydrated-reactivated under various operating conditions and submitted to microstructural analyses, in order to elucidate the interrelationships among reactivation operating conditions, physico-chemical characteristics of reactivated wastes and their desulphurizing ability. For reactivated bed ashes, whose SO2 uptake capacity was also evaluated through resulphation tests, the CaO conversion to Ca(OH)2 was complete even at the shortest time (30 min) and the lowest temperature (200°C) of hydration, while CaSO4 was not involved in any reaction process. Only minor compositional differences related to secondary constituents (still unreacted or hydrated phases) were found. Accordingly, the best results in terms of accessible porosity and sulphation performance were obtained with less severe hydration treatments. For the ultimate resulphation degree, values never lower than 74% were obtained and a maximum of 94% was achieved.
Steam Hydration-Reactivation of FBC Wastes for Enhanced In Situ Desulphurization: the Influence of Operating Conditions
TELESCA, ANTONIO;VALENTI, Gian Lorenzo;
2008-01-01
Abstract
Four FBC bed ashes were steam hydrated-reactivated under various operating conditions and submitted to microstructural analyses, in order to elucidate the interrelationships among reactivation operating conditions, physico-chemical characteristics of reactivated wastes and their desulphurizing ability. For reactivated bed ashes, whose SO2 uptake capacity was also evaluated through resulphation tests, the CaO conversion to Ca(OH)2 was complete even at the shortest time (30 min) and the lowest temperature (200°C) of hydration, while CaSO4 was not involved in any reaction process. Only minor compositional differences related to secondary constituents (still unreacted or hydrated phases) were found. Accordingly, the best results in terms of accessible porosity and sulphation performance were obtained with less severe hydration treatments. For the ultimate resulphation degree, values never lower than 74% were obtained and a maximum of 94% was achieved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
