ABSTRACT
The increasing importance of natural gas as a source of energy poses difcult gas separation design challenges, as the streams recovered from gas elds 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
10.1 Introduction .................................................................................................. 310 10.2 Antecedents .................................................................................................. 310 10.3 Gas Purication ............................................................................................ 312
10.3.1 Rate of Gas Absorption .................................................................... 314 10.3.2 Stage Equilibrium Gas Absorption ................................................... 315
10.3.2.1 Single-Component Absorption .......................................... 316 10.4 Membrane Gas-Liquid Contactors............................................................... 319
10.4.1 Types of Membrane Contactors ........................................................ 320 10.4.2 Design Considerations for Membrane Gas-Liquid Contactors ........ 322
10.5 Fundamental Aspects in Chemical Absorption ............................................ 324 10.5.1 Complex Chemical and Phase Equilibrium ...................................... 325
10.6 Mass-Transfer Fundamentals ........................................................................ 326 10.6.1 Mass-Transfer Models ....................................................................... 328 10.6.2 Application of Absorption Process ................................................... 328
10.6.2.1 Vapor-Liquid Equilibrium Model ..................................... 329 10.6.2.2 Kinetics Model ................................................................... 329 10.6.2.3 Process Simulation Model ................................................. 330
10.6.3 Resume ............................................................................................. 333 10.6.3.1 Case of Ammonia Removal from Wastewater through
Combination of Absorption Process in the Membrane Contactor and Advance Oxidation Process in Hybride Plasma-Ozone Reactor ....................................................... 333
10.7 Conclusions ................................................................................................... 336 10.7.1 Effect of Biologically Produced Sulfur on Gas Absorption
in a Biotechnological Hydrogen Sulde Removal Process .............. 337 10.8 Future Prospects ........................................................................................... 338 References .............................................................................................................. 338
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 elds 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.
