Calcium looping

Calcium looping (CaL), or the regenerative calcium cycle (RCC), is a second-generation carbon capture technology.wikipedia
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Carbon capture and storage

carbon captureCCScarbon capture and sequestration
Calcium looping (CaL), or the regenerative calcium cycle (RCC), is a second-generation carbon capture technology. The captured carbon dioxide can then be transported to a storage site, used in enhanced oil recovery or used as a chemical feedstock.
A variant of chemical looping is calcium looping, which uses the alternating carbonation and then calcination of a calcium oxide based carrier as a means of capturing.

Calcium carbonate

CaCO 3 calcareouscalcium
In the calcium looping process, the two species are calcium carbonate (CaCO 3 ) and calcium oxide (CaO).

Calcium oxide

quicklimelimeCaO
In the calcium looping process, the two species are calcium carbonate (CaCO 3 ) and calcium oxide (CaO).

Carbon sequestration

sequestrationsequesteredsequester
The captured carbon dioxide can then be transported to a storage site, used in enhanced oil recovery or used as a chemical feedstock.

Enhanced oil recovery

enhanced recoveryEORFireflooding
The captured carbon dioxide can then be transported to a storage site, used in enhanced oil recovery or used as a chemical feedstock.

Carbon capture and utilization

Carbon Capture & Sequestrationcarbon capture and utilisationcarbon utilization or storage
The captured carbon dioxide can then be transported to a storage site, used in enhanced oil recovery or used as a chemical feedstock.

Amine gas treating

Amine treatingamine scrubbingacid gas removal
Calcium looping is being developed as it is a more efficient, less toxic alternative to current post-combustion capture processes such as amine scrubbing.

Cement

hydraulic cementcement plantcement factory
It also has interesting potential for integration with the cement industry.

Calcination

calcinedcalciningcalcine
The forward, endothermic step is called calcination while the backward, exothermic step is carbonation.

Carbonation

carbonatedcarbonated beveragessoda carbonate
The forward, endothermic step is called calcination while the backward, exothermic step is carbonation.

Endothermic process

endothermicendothermic reactionendothermic reactions
The forward, endothermic step is called calcination while the backward, exothermic step is carbonation.

Exothermic process

exothermicexoergicexothermic reaction
The forward, endothermic step is called calcination while the backward, exothermic step is carbonation.

Cyclonic separation

cyclonecyclonesCyclonic
The calciner and carbonator are fluidised beds with associated process equipment for separating the gases and solids attached (such as cyclones).

Fluidized bed combustion

fluidised bed combustionfluidized bedCFB
Direct provision of heat involves the combustion of fuel in the calciner itself (fluidised bed combustion).

Oxy-fuel combustion process

oxy-fueloxy-combustionoxy-fuel combustion
The heat necessary for calcination can be provided by oxy-combustion of coal below.

Air separation

cryogenic distillationCryogenic Air Separationseparation of air
The provision of oxygen for the combustion uses lots of electricity; other air separation processes are being developed.

Rankine cycle

Rankinesteam cycleRankine engine
Although the heat from the carbonator is not at a high enough temperature to be used in the calciner, the high temperatures involved (>600 °C) mean that a relatively efficient Rankine cycle for generating electricity can be operated.

Exergy

exergeticaboveavailable energy
The low temperature of this heat means that it contains much less exergy and can generate much less electricity through a Rankine or organic Rankine cycle.

Organic Rankine cycle

ORC turbineorganic chemicals such as refrigerantsOrganic Rankine
The low temperature of this heat means that it contains much less exergy and can generate much less electricity through a Rankine or organic Rankine cycle.

Calcium sulfate

calcium sulphateCaSO 4 Drierite
Because calcium sulfate has a greater molar volume than either CaO or CaCO 3 a sulfated layer will form on the outside of the particle, which can prevent the uptake of CO 2 by the CaO further inside the particle.

Fluidized bed

fluidized-bedcirculating fluidised bed (CFB)Dual Fluidized Bed
Firstly, both carbonator and calciner can use fluidized bed technology, due to the good gas-solid contacting and uniform bed temperature.

Diffusion

diffusediffusesdiffusive
This product layer grows over the pores and seals them off, forcing carbonation to follow a slower, diffusion dependent mechanism.

Sintering

sinteredsinterPressureless sintering
CaO is also prone to sintering, or change in pore shape, shrinkage and grain growth during heating.

Lattice diffusion coefficient

lattice diffusion
Ionic compounds such as CaO mostly sinter because of volume diffusion or lattice diffusion mechanics.

London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter

Marine DumpingConvention on the Prevention of Marine Pollution by Dumping of Wastes and Other MatterLondon Convention
Ocean disposal was found to be the best, but current laws relating to dumping waste at sea prevent this.