The effect of CO_2 or steam partial pressure in the regeneration of solid sorbents on the CO_2 capture efficiency in the two-interconnected bubbling fluidized-beds system

摘要

The effect of CO_2 or steam partial pressure in the regeneration of CO_2 solid sorbents was studied in the two-interconnected bubbling fluidized-beds system. Potassium-based dry solid sorbents, which consisted of 35 wt% K_2CO-3 for CO_2 sorption and 65 wt% supporters for mechanical strength, were used. To investigate the CO_2 capture efficiency of the regenerated sorbent after the saturated sorbent was regenerated according to the CO, or steam partial pressure in the regeneration, the mole percentage of CO_2 in the regeneration gas was varied from 0 to 50 vol% with N_2 balance and that of steam was varied from 0 to 100 vol% with N_2 balance, respectively. The CO_2 capture efficiency for each experimental condition was investigated for one hour steady-state operation with continuous solid circulation between a carbonator and a regenerator. The CO_2 capture efficiency decreased as the partial pressure of CO_2 in the flu-idization gas of the regenerator increased, while it increased as that of steam increased. When 100 vol% of steam was used as the fluidization gas of the regenerator, the CO_2 capture efficiency reached up to 97% and the recovered CO, concentration in the regenerator was around 95 vol%. Those results were verified during 10-hour continuous experiment.