Sunday, July 19, 2009

Carbon Capture Technology Demo in Hometown Kenosha Wisconsin

I was surprised to see in C&E News that WE Energies Pleasant Prairie Power Plant has carbon sequestration plant -- actually pilot plant. I drove past this plant every day for years, and brother Doug actually worked during college as a laborer building that plant.

I remember when they put up a new stack, WE Energies said they were putting in new anti-pollution devices, and the original design was one of the largest polluters in the area. I was surprised at how far away the chimney/stack was from the old boiler. This schematic shows the steps that the exhaust gases are going through, and why they need the space.

It turns out that a Swiss conglomerate Alstrom has put up a pilot plant treating 1% of the output and trapping the CO2. Alstrom is a big company, and does not publish a lot of its technology. I looked up their carbon capture patent, and it does not say much. It says we are going to put in a wheel shaped device to capture CO2 and use it on the cooled exhaust gases. They also have a schematic flowchart that seems so very generic. I am surprised they can describe a powerplant technology in six pages including 2 large pictures. At work we can take 3o pages to describe a new paint resin. The schematic below is from a magazine article, and it is better, but still to vague to see what is really happening.

This technology uses ammonia to capture the carbon dioxide at low temperature -- recall that carbon dioxide is a weak acid, and ammonia is a fairly strong base. Alstrom claims they can capture 90%. The trick is to capture at a low temperature, and try to regenerate the ammonia by releasing the carbon dioxide at a higher temperature. Billions are coming from the US ($6 billion) and foreign economic stimulus bills to work on this problem.

A key problem is what to do with the carbon dioxide, and this is unsolved. People talk about injecting far underground, or putting at the bottom of the sea. I think that Alstrom is proposing to sell this carbon dioxide on the merchant gas market. There are uses for carbon dioxide, but not in the huge amounts needed.

There are two PR videos on the plant on youtube. Basic tour. CO2 tour Interesting, but not great.

The picture at right is the actual plant. Obviously it is pretty small for a plant this size -- almost a toy.

Why is this interesting? Here is a linkage between the biggest global issue and the concrete hometown issues. I am not sure that anything can be done for global warming, because the problem is too large. I don't know. We should research clever solutions to the problem.