Why can't the Govt insist on power stations, etc. doing this;
5. CO2 CAPTURE CO2-capture processes or decarbonisation technologies can be divided into three main categories or general process routes: ? Post-combustion processes. Carbon dioxide is captured from a flue gas at low pressure (1 bar) and low CO2-content (3-20%), in general. The separation task is to remove CO2 from a mixture of mainly nitrogen and oxygen, but also the impact of flue gas impurities (SOx, NOx, particulates) needs to be taken into account. ? Pre-combustion processes. Carbon dioxide is captured from a gas mixture with predominantly H2 gas at high pressure (15-40 bar) and medium CO2-content (15-40%) or carbon is produced directly from fossil fuels. Apart from the CO2/H2 separation, the feed gases also contain CO, H2S and sometimes other sulphur components. ? Denitrogenation processes, more often referred to as oxyfuel. A concentrated stream of carbon dioxide can be produced by the exclusion of nitrogen before or during the combustion/conversion process. The difference with the previous process routes is that here the separation is targeted to produce oxygen from air (i.e. separation of oxygen from mainly nitrogen), thereby avoiding the need for CO2 separation. An additional advantage might be that in the same process all impurities are captured, as the process is essential free of flue gas.
5.1 The case for post-combustion CO2 capture The post-combustion capture process (PCC) is the process which is the easiest to use as a retrofit option, allowing CO2 to be captured from the existing coal fired power stations. The state-of-the-art CO2 separation technology is based on a liquid absorbent which undergoes a reversible chemical reaction with CO2. These chemical absorption processes are in general applicable to gas streams at both high and low overall process pressure, but most applicable where a CO2 is present at low concentration. The regeneration of the chemical absorbent is carried out at elevated temperatures (100 ? 140 oC) and pressures not very much higher than the atmospheric pressure. The typical flow sheet of CO2 recovery using chemical solvents is shown in Figure 1., ....... etc
The liquid absorbent technology is commercially available and already in use for a wide range of gas separation applications. Hence, it presents a relatively low technology risk for deployment in comparison to other less developed technologies.
PCC has never been used at full-scale and integrated in a coal fired power plant. Capture of 90% of the CO2 present in flue gases from a coal-fired power plant would result in a 30% efficiency loss when using a standard liquid absorbent process. The resulting loss of the output product, i.e. the electricity sent out to the customers, is an important draw-back and quite different from other applications of this technology, where product losses would be minimal.
As an end-of-pipe technology a PCC process also provides added flexibility. For instance, the capture plant can be switched off if need be, to allow for a larger output of the power plant at times when electricity demand is high and market prices are high. This is a beneficial feature in the highly competitive Australian Electricity Market. Such flexible operation allows the technology to be in tune with market requirements. A liquid absorbent based technology also allows for easy incorporation of technological improvements. As the performance of liquid absorbent will gradually be improved, replacement of the liquid absorbent in the existing equipment is a practice which is widely used in other applications. The improved performance can be used to increase output or increase overall efficiency. As such the technology is applicable in new and retrofit applications, thus providing a broad pathway towards CO2-emission reductions from coal fired power stations. There is large global targeted R&D activity addressing the challenges for application of liquid absorbent based technologies for CO2 capture. These challenges are not only related to the efficiency penalty, but also to the chemical ....... etc
FROM what it says here, 90% of CO2 can be removed from flue stacks, although there is loss of efficiency for power generation but whenever required , they can increase power output "when enrgy demand is high".
WHY is there not more open DISCUSSION about this, to weigh up the costs and benefits compared to the POLITICIANS new tax being peddled by AUSTRALIA's best door to door salesperson ??
RAVI
ps. I phoned the author of the report, but had to leave a message and then phoned and spoke to CSIRO, who passed me onto the Climate Change 1800 number and emailed me Wikipaedia links. Neither could/would/or allowed to discuss politics ?, only Govt.'s official spiel.
