Talk:Conventional coal-fired power plant/Draft

Wikipedia has a similar article (i.e., "Fossil fuel power plant")

I was a substantial contributor to the WP article. It has been completely re-written and reformatted before uploading here as a CZ article. However, it still contains some of the WP content. Milton Beychok 06:41, 21 November 2008 (UTC)

Environmentalists

Milton, I read it, found it interesting, and added a few small things. To me it seems that in the section about CO2 emission the opinion of the environmentalists must be heard. Of course, carbon/coal is the worst fuel from the point of view of CO2 emission and therefore there is fierce resistance against the construction of new coal-powered plants (by the same people who resist nuclear-powered plants and advertise the use of electric cars). But CZ needs to voice this opinion as well. --Paul Wormer 10:37, 9 December 2008 (UTC)

Paul, thanks for your comments. As clearly noted in the main article, the CO2 and Radioactive Nuclide sections have not yet been written (as of December 9, 2009). When I write those sections, they will receive the same detailed discussion as provided in the Particulate Matter, SO2 and NOx sections. Milton Beychok 17:53, 9 December 2008 (UTC)

CO2 emission

Milton, I don't quite understand why the carbon content of coal has great influence on the emission of a 500 MW plant. When the carbon content is lower, combustion enthalpy is also lower, and more coal must be burned to achieve the 500 MW. My guess would be that the ratio CO2-emission/energy of coal is more or less constant. I can understand a certain influence when heat of combustion is delivered (in non-negligible amount) by compounds in coal other than pure carbon. Is that the case?

Of course, I see that the thermal efficiency of the plant is also an important factor, as you point out.--Paul Wormer 11:17, 19 December 2008 (UTC)

Paul, if coal is completely combusted and no auxiliary equipment is involved in that combustion, then you are correct ... the carbon content of the coal would not usually effect the amount of CO2 emissions.

However, in a coal-fired power plant, the coal must be transported and crushed and that requires plant internal usage of electric power. Removal of the bottom ash requires plant internal usage of electric power. Removal of the fly ash with electrostatic precipitators requires internal plant usage of electric power. A lower carbon content coal means more coal is required (as you noted) and therefore the plant's internal usage of electricity increases ... which decreases the net output of electricity and hence the overall plant efficiency is decreased.

Also, if a lower carbon content is accompanied by a higher ash content in the coal, that may mean that more unburned carbon is lost in the ash and therefore the combustion efficiency is reduced. Also again, if a lower carbon content is accompanied by a higher hydrogen content, then some of the energy release in the combustion is derived from combustion of hydrogen rather than carbon which would affect the amount of carbon dioxide emissions.

All of the above items affect the carbon dioxide emissions. Admittedly, they are not very large effects, but they are significant. - Milton Beychok 20:29, 19 December 2008 (UTC)