With regards to elemental emissions from limestone use during the calcium looping cycle for CO2 capture, Dean [14] carried out experiments at the bench scale to investigate the effect of coal use on limestone-derived sorbent trace element inventory. Experiments carried out without coal use showed no change in sorbent trace element inventory. Batch experiments carried out using La Jagua coal showed an increase in the concentration of Ba, Cr, K, Mn, Sr, and Ti, whilst concentrations of B, Na and K remain the same, whilst for Cu there was a small decrease. For continuous experiments comparing 2 different coals and refuse-derived fuel (RDF), an increase in Al content was observed suggesting some ash mixed in with the sorbent. The concentrations of Ba, K, Sr and Zn remained the same for all fuels. For Lea Hall coal, there was an increase in B over eight cycles from ∼20 to 40 ppm, though not for La Jagua. For Cu, sorbent concentrations in the first cycle (∼15 ppm) remained the same over eight cycles for the two coals, but increased over five cycles in the presence of RDF from ∼20 ppm to ∼180 ppm. Na remained the same for the sorbent cycled in the presence of La Jagua, but there was an increase in results for Lea Hall coal and RDF from ∼250 to ∼550 ppm and from ∼200 to 400 ppm respectively, expected given that the Na content of the La Jagua coal is an order of magnitude lower than of the other two fuels. Ti remained the same for La Jagua over eight cycles, though saw an increase in the sorbent cycled in the presence of RDF over five cycles from ∼50 ppm to ∼150 ppm. There appear to be no further studies available in the literature investigating elemental partitioning as a result of limestone use in the calcium looping cycle.
limestone
B
from ∼20 to 40 ppm
ppm
different coals
2
cycles
eight
cycle
first
sorbent
Cu
∼15 ppm
ppm
cycles
eight
coals
two
cycles
five
sorbent
Cu
from ∼20 ppm to ∼180 ppm
ppm
sorbent
Na
from ∼250 to ∼550 ppm
ppm
sorbent
Na
from ∼200 to 400 ppm
ppm
fuels
two
cycles
eight
cycles
five
sorbent
Ti
from ∼50 ppm to ∼150 ppm
ppm