Economic implications Calcium looping

1 economic implications

1.1 cost per metric ton co2 captured
1.2 cost of co2 emissions avoided through ca-looping
1.3 cement production

economic implications

calcium looping has several economic advantages.

cost per metric ton co2 captured

firstly, ca-looping offers greater cost advantage compared conventional amine-scrubbing technologies. cost/metric ton co2 captured through ca-looping ~$23.70 whereas co2 captured through amine scrubbing $35–$96. can attributed high availability , low cost of cao sorbent (derived limestone) compared mea. also, discussed in section 2, ca-looping imposes lower energy penalty amine scrubbing, resulting in lower energy costs. amine scrubbing process energy intensive, approximately 67% of operating costs going steam requirements solvent regeneration. more detailed comparison of ca-looping , amine scrubbing shown below.

table i: comparison of ca-looping , amine scrubbing

cost of co2 emissions avoided through ca-looping

in addition, cost of co2 emissions avoided through ca-looping lower cost of emissions avoided via oxyfuel combustion process (~$23.8usd/t). can explained fact that, despite capital costs incurred in constructing carbonator ca-looping, co2 not captured oxy-fired combustion, main combustor (before carbonator). oxygen required in calciners 1/3 required oxyfuel process, lowering air separation unit capital costs , operating costs. sensitivity analysis: figure 3 shows how varying 8 separate parameters affects cost/metric ton of co2 captured through ca-looping. evident dominant variables affect cost related sorbent use, ca/c ratio , cao deactivation ratio. because large sorbent quantities required dominate economics of capture process.

these variables should therefore taken account achieve further cost reductions in ca-looping process. cost of limestone largely driven market forces, , outside control of plant. currently, carbonators require ca/c ratio of 4 effective co2 capture. however, if ca/c ratio or cao deactivation reduced (i.e. sorbent can made work more efficiently), reduction in material consumption , waste can lower feedstock demand , operating costs.

cement production

finally, favorable economics can achieved using purged material calcium looping cycle in cement production. raw feed cement production includes ~ 85 wt% limestone remaining material consisting of clay , additives (e.g. sio2, al2o3 etc.). first step in process involves calcinating limestone produce cao, mixed other materials in kiln produce clinker.

using purged material ca-looping system reduce raw material costs cement production. waste cao , ash can used in place of caco3 (the main constituent cement feed). ash fulfill aluminosilicate requirements otherwise supplied additives. since on 60% of energy used in cement production goes heat input precalciner, integration ca-looping , consequent reduced need calcination step, lead substantial energy savings (eu, 2001). however, there problems using waste cao in cement manufacture. example, adding ca-looping coal-fired plants in uk generate enough waste 33 mtonnes/yr of cement production, whereas current cement production in uk 12.5 mtonnes/yr. hence, if technology applied on large scale, purge rate of cao should optimized minimize waste.