Carbon dioxide scrubber

A carbon dioxide scrubber is a device which absorbs carbon dioxide (CO₂). It is used to treat exhaust gases from industrial plants or from exhaled air in life support systems such as rebreathers or in spacecraft, submersible craft or airtight chambers. Carbon dioxide scrubbers are also used in controlled atmosphere (CA) storage. They have also been researched for carbon capture.

The dominant application for CO₂ scrubbing is for removal of CO₂ from the exhaust of coal- and gas-fired power plants. Virtually the only technology being seriously evaluated involves the use of various amines, e.g. monoethanolamine. Cold solutions of these organic compounds bind CO₂, but the binding is reversed at higher temperatures:

As of 2009^[update], this technology has only been lightly implemented because of capital costs of installing the facility and the operating costs of utilizing it.

Several minerals and mineral-like materials reversibly bind CO₂. Most often, these minerals are oxides, and often the CO₂ is bound as carbonate. Carbon dioxide reacts with quicklime (calcium oxide) to form limestone (calcium carbonate), in a process called carbonate looping. Other minerals include serpentinite, a magnesium silicate hydroxide, and olivine.Molecular sieves also function in this capacity.

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