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http://www.geos.ed.ac.uk/sccs/capture/precombustion.html

Pre-Combustion Capture

Pre-combustion capture involves removal

of CO2 prior to combustion, to producehydrogen. Hydrogen combustion producesno CO2 emissions, with water vapourbeing the main by-product. Provided thatthis technology is used with carbonstorage it could provide a CO2emissionfree fuel for the future.

The capture process consists of three stages; firstly the hydrocarbon fuel (tinto hydrogen and carbon monoxide (CO) to form a synthesis gas. The secreacting it with water and which is known as shift conversion. Finally, thethen be combusted cleanly. The CO2 can then be compressed into liquid a

Pros:

Proven industrial scale technology in oil refineries, but needs 3x

scale-up for power plants. 90-95% of CO2 emissions can be captured.

Applicable to natural gas, and to coal fired IGCC power plants.

Lowest technology risk, and may become the most efficientmethod.

Can produce H2 as transportable energy vector, or liquid fuels fromcoal - but penalties on efficiency.

Cons:

http://www.geos.ed.ac.uk/sccs/capture/precombustion.htmlhttp://www.co2captureproject.com/http://www.co2captureproject.com/http://www.sccs.org.uk/http://www.geos.ed.ac.uk/sccs/capture/precombustion.html

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Requires a chemical plant in front of gas turbine.

High investment cost of dedicated new-build plant.

High NOx emissions will require expensive scrubbers.

Efficiency of H2 burning turbines is lower than conventionalturbines.

May be less flexible under varying electicity generation marketrequirement, so base load preferred.

Carbon Dioxide Capture

CO2 capture is theprocess of removingCO2 (carbon dioxide)produced byhydrocarboncombustion (coal, oiland gas) before itenters the atmosphere.

The process will bemost cost effectivewhen it is used onlarge point sources ofCO2such as powerstations and industrial

http://www.co2crc.com.au/

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plants. These currently make up more than half of allman-made CO2 emissions.

CO2 capture is an existing industrial technologywidely used, on a smaller scale, in the manufactureof fertilizers, the food-processing industry and withinthe oil and gas sector. The main challenge for anycapture process is the low concentration of CO2inthe flue gas. Depending on the industrial sourceCO2 content can vary from a few percent to wellover fifty percent. Other contaminant gases such asoxygen, sulphur oxides, water vapour and nitrogencan also be present in flue gases. For reasons of botheconomic and energy costs it would be impossible tocompress and store all of them. Therefore CO2 mustbe preferentially separated from the other flue gasesby a capturing process.

There are currently three main methods of capturingCO2:

Post-combustion capturePre-combustion captureOxy-fuel combustion capture

Read more about current research intoCarbon Capture processes

http://www.geos.ed.ac.uk/sccs/capture/postcombustion.htmlhttp://www.geos.ed.ac.uk/sccs/capture/precombustion.htmlhttp://www.geos.ed.ac.uk/sccs/capture/oxyfuel.htmlhttp://www.geos.ed.ac.uk/sccs/capture/research/http://www.geos.ed.ac.uk/sccs/capture/research/http://www.geos.ed.ac.uk/sccs/capture/postcombustion.htmlhttp://www.geos.ed.ac.uk/sccs/capture/precombustion.htmlhttp://www.geos.ed.ac.uk/sccs/capture/oxyfuel.htmlhttp://www.geos.ed.ac.uk/sccs/capture/research/http://www.geos.ed.ac.uk/sccs/capture/research/