Abstract

The increasing importance of natural gas as a source of energy poses difficult gas separation design challenges, as the streams recovered from gas fields are at high pressures (typically about 10 MPa) and can contain a high proportion of CO₂ (up to 70%). In addition, as the implementation of the Kyoto protocol would require the capture of large quantities of CO₂, its injection in depleted or near-depleted reservoirs for enhanced oil/gas recovery operations will become increasingly frequent. This is likely to result in natural gas streams that are even richer in CO₂. Conventional separation techniques are usually restricted to low CO₂ content or low-pressure feeds, and consequently there is a pressing need for an alternative process that is appropriate for such a scenario. However, absorption processes are aimed at the separation of CO₂ if there are a range of applications in various fields of chemical engineering, biochemistry, environmental, metallurgy, biotechnology, and others. Therefore, this chapter also discusses some basic aspects of the absorption process and some general applications show the versatility and usefulness of this ancient and current unitary process.