Carbon Dioxide Separation Methods And Their Advantages And Disadvantages

Methods used for Carbon dioxide Removal:

Membrane Separation: (1)

Advantages:

• Membrane processes generally do not require a phase alteration to make a separation. As a result, energy supplies will be low unless a great deal of energy needs to be used to increase the pressure of a feed stream in order to drive the infusing component(s) across the membrane.

• Membrane processes present essentially a very simple flow-sheet. There are no moving parts (except for pumps or compressors), no multifaceted control schemes, and little ancillary equipment likened to many other processes. As such, they can offer a simple, easy-to-operate, low upkeep process option.

• Membranes can be produced with tremendously high selectivity for the components to be

• Certain colloidal solids can permanently vulgar the membrane surface.

• The energy cost is advanced than chemical treatment, although less than evaporation.

• Synthetics are not effectively dried by this method.

• A major disadvantage of this procedure is low CH4 yield. The waste gas still contains CH4 which is highly contaminating for the environment

Solvents Used in Carbon dioxide Capturing: (1, 2, 3, 4, 5, 6)

Preoccupation is a physical solvent relies on the solubility of Carbon dioxide in the solvent rather than chemical reaction with the solvent. The solvent is redeveloped by changing by pressure or temperature.

Absorption can be approved out with the help of following solvents:

Carbonates:

CO2 + K2CO3 + H2O ⇔ 2KHCO3

Drawback of Using Carbonates:

The hot potassium carbonate process, industrialized by the Bureau of Mines, has been applied widely in recent years to carbon dioxide elimination in the purification of hydrogen and natural gas.

The difficulty of a hot carbonate system is the incapability to secure a satisfactory degree of clean up in the cleaned gas except with very large towers, a more complex process cycle or even a second absorber at high

The most widely used for sweetener of natural gas are aqueous resolutions of alkanolamines. They are generally used for bulk elimination of CO2 and H2S. The low working cost and flexibility of tailoring solvent composition to suit gas arrangements make this process one of the most commonly designated. A liquid physical solvent can be additional to the amine to recover selectivity.

The acid gas is fed into a scrubber to eliminate entrained water and liquid hydrocarbons. The gas then enters the bottommost of absorption tower. The sweet gas leavings at the top of tower. The renewed amine or lean amine enters at the top of this tower and the two streams are communicated counter currently. In this tower, carbon dioxide and hydrogen disulfide are engrossed with the chemical reaction into the amine haze.

The departure amine solution, loaded CO2 and H2S, is named rich amine. This stream is rushed, filtered, and then fed to the top of a stripper to recuperate the amine, and acid gases (CO2 and H2S) are stripped and exit at the top of the tower. The refluxed water helps in watercourse stripping the rich amine solution. The generated amine or lean amine is recycled back to the top of the absorption