▁the ▁method ▁can ▁be ▁implemented ▁using ▁large - scale ▁circul ating ▁fluid ized ▁b eds ▁while ▁other ▁methods ▁such ▁as ▁am ine ▁scr ub bing ▁is ▁required ▁a ▁vast ly ▁ups c ale ▁sol vent ▁scr ub bing ▁to wers . ▁ ▁In ▁addition , ▁cr ushed ▁lim estone ▁used ▁in ▁calci um ▁looping ▁as ▁the ▁sor b ent ▁is ▁a ▁natural ▁product , ▁which ▁is ▁well ▁distributed ▁all ▁over ▁the ▁world , ▁non - h az ard ous ▁and ▁in exp ensive . ▁Many ▁c ement ▁manufact ur ers ▁or ▁power ▁plants ▁located ▁close ▁to ▁lim estone ▁sources ▁could ▁conce iv ably ▁employ ▁Cal ci um ▁looping ▁for ▁CO 2 ▁ ▁capture . ▁The ▁waste ▁sor b ent ▁can ▁be ▁used ▁in ▁c ement ▁manufact ure . ▁ ▁Draw back s ▁ ▁A part ▁from ▁these ▁advantages , ▁there ▁are ▁several ▁dis adv antages ▁needed ▁to ▁take ▁into ▁consider ations . ▁ ▁The ▁plant ▁integr ating ▁Ca - Loop ing ▁might ▁require ▁a ▁high ▁construction ▁invest ment ▁because ▁of ▁the ▁high ▁thermal ▁power ▁of ▁the ▁post - comb ust ion ▁calci um ▁loop . ▁The ▁sor b ent ▁capacity ▁decre ases ▁significantly ▁with ▁the ▁number ▁of ▁cycles ▁for ▁every ▁carbon ation - calc ination ▁cycle ▁so ▁the ▁calci um - loop ing ▁unit ▁will ▁require ▁a ▁constant ▁flow ▁of ▁lim estone . ▁In ▁order ▁to ▁increase ▁the ▁long - term ▁react ivity ▁of ▁the ▁sor b ent ▁or ▁to ▁react iv ate ▁the ▁sor b ent , ▁some ▁methods ▁are ▁under ▁investigation