4: Electricity Decarbonization, 100
mW(e) CC Steam Module
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100 mW(e) Carbon Capture
Loeffler Steam Generation Module
(Salvaging Outlawed Coal Power Plants)
25% of the stack emissions of concrete and steel plants are CO2. Coal plants are about 12%, oil 7%, natural gas 4%.
Air has a 0.04% CO2 content.
Steam Generator Teamed Up With Coal Peaking
Transitioning the world to getting the big electricity civilization needs from clean carbon capture.
Cleaver Brooks, Inc.
(Above) Using carbon capturing for BASELOAD electricity while continuing to use coal for INTERMEDIATE and PEAK load times.
Every coal plant has an annual load distribution curve not terribly unlike the one above. Using the curve above as a generalized template, you can find a ratio between carbon captured steam and coal steam that will, over a year's time, match or better the EPA's pounds of CO2 per megaWatt-hour of gross electricity produced.
Example: If the coal CO2 component of your plant happens to produce 2,000 lb CO2 per mWh, and the EPA limit for this particular type of electricity generating unit is 1,400 lb CO2 per mWh, you need only to produce at the end of the year enough zero-CO2 carbon captured electricity to dilute the plant's total annual electricity CO2 emissions down to a level that is less than the EPA's CO2 emissions standard.
This should be achievable using equipment far smaller, cheaper, and less energy-consuming than what would be necessary to capture all the CO2 produced by the plant. - - Just thinking.
Example: Your author has a very typical (but real)
and steam turbine generator in mind:
Boiler: Main Steam 1,106,000 lbs per hour at 1,890 psi and 1,005°F. Reheated Steam 964,000 lbs per hour at 507 psi and 1005°F.
Generator: 160,000kW, 18,000 Volt, 3 phase, 60 cycle, hydrogen cooled, static excitation.
According to the good folks at Linde Oxygen, it takes
about one ton of oxygen to make 1 megaWatt-hour of electricity.
If we use the Wisconsin load demand chart above as a template, the author's favorite steam plant would have about 3/7 (0.43) of its net capacity (0.43 x 160 mWh or 69 mWh) dedicated to baseload. That means the oxygen plant should be able to produce about 70 tons of oxygen per hour for the net electricity plus about 16 additional tons to make the electricity needed to power the parasitic losses caused by the carbon capture equipment. Perhaps 86 tons of oxygen per hour. That's a far smaller air reduction unit than the 160 + 40 = 200 tons per hour unit that would be needed to enable 100% carbon capture.
Also, (0.43 + 0.11) x 1,106,000 lbs of steam per hour = 597,240 lbs/hr. Again, a far smaller HRSG (Heat Recovery Steam Generator) would be needed.
Depending upon your actual annual load profile and emissions, you might be able to meet your needs with 1/7 oxyfuel capacity. Taking this approach even further, simply powering the HRSG with biodiesel gives you carbon-neutral steam and you could skip the oxyfuel and carbon capture part.
AND, since the
coal steam part of your plant wasn't touched, bad carbon capture equipment days
would just be low emissions coal days.
Cleaning up industrial grade carbon dioxide:
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