Information om CO2-fangst og CO2-lagring
(Carbon Capture and Storage - CCS)
Merenergiforbrug i opsamlingsleddet
Kildernes angivne merenergiforbrug er vist med fed i rødt.
IPCC (2005) opererer med intervallet 24-40 % for kulfyrede kraftværker (Pulverized Coal plants).
IEA (2004) 39 %
I en artikel (januar 2009): The energy penalty of post-combustion CO2 capture & storage and its implications for retrofitting the U.S. installed base (Kurt Zenz House, Charles F. Harvey, Michael J. Aziz and Daniel P. Schrag) konkluderer forfatterne, at merenergiforbruget i forbindelse med eftermonterede (retrofit) CCS anlæg på kulkraftværker er i størrelsesordenen 50-80 % og at merenergiforbruget i praksis vanskeligt kan bringes under 25 %.
Achieving substantial reductions in CO2 emissions requires either shutting down a large fraction of the current installed base of coal-fired power plants or retrofitting those plants for CCS. Previous studies have estimated that the additional fuel required (f2) to maintain constant work output for a PC retrofit is between 50% and 80%. An analysis of the thermodynamic limit indicates those values might be improved by harnessing more of the available waste heat and by improving the 2nd-law efficiency of temperature-swing separation systems. It appears difficult, however, to improve f2 for post-combustion capture to below 25% in practice. Our most likely efficiency scenario indicates that offsetting the energy penalty incurred from capturing and storing 80% of the U.S. coal fleet’s CO2 emissions will require either an additional 390–600 million tonnes of coal, an additional 69–92 gigawatts of CO2-free-baseload power, or a 15%–20% reduction in overall electricity use.”
I en Panel Presentation, (maj 2007): CO2 Compression Opportunities in Fossil Fueled Power Plants. Session Chairs: Richard Dennis and Manfred Klein hedder det bl.a.:
"When 90% CO2 capture is implemented in a precombustion decarbonization IGCC and CO2 is compressed to 2,200 psia, the auxiliary power load increases by about 40 %, compared to the non-capture case."
I et abstract af artiklen Carbon capture and storage: Fundamental thermodynamics and current technology af S.C. Page, A.G.Williamson og I.G.Mason hedder det:
"Carbon capture and storage (CCS) is considered a leading technology for reducing CO2 emissions from fossil-fuelled electricity generation plants and could permit the continued use of coal and gas whilst meeting greenhouse gas targets. However considerable energy is required for the capture, compression, transport and storage steps involved. In this paper, energy penalty information in the literature is reviewed, and thermodynamically ideal and ‘‘realworld’’ energy penalty values are calculated. For a sub-critical pulverized coal (PC) plant, the energy penalty values for 100% capture are 48.6% and 43.5% for liquefied CO2, and for CO2 compressed to 11MPa, respectively. When assumptions for supercritical plants were incorporated, results were in broad agreement with published values arising from process modelling. However, we show that energy use in existing capture operations is considerably greater than indicated by most projections. Full CCS demonstration plants are now required to verify modelled energy penalty values. However, it appears unlikely that CCS will deliver significant CO2 reductions in a timely fashion. In addition, many uncertainties remain over the permanence of CO2 storage, either in geological formations, or beneath the ocean. We conclude that further investment in CCS should be seriously questioned by policy makers."
I en artikel af Mark Z. Jacobson og Mark A. Delucch i Energy Policy: Providing all global energy with wind, water, and solar power, Part I: Technologies, energy resources, quantities and areas of infrastructure, and materials (2010) hedder det :
CCS will actually "increase such emissions and of air pollutants per unit of net delivered power and will increase all ecological, land-use, air-pollution, and water-pollution impacts from coal mining, transport, and processing, because the CCS system requires 25% more energy, thus 25% more coal combustion, than does a system without CCS".
Opdateret november 2016