Gaseous Emissions

I was reading my daily NYTimes e-mail of current articles yesterday when I came across this. I was going to write something about it, but I got distracted. Then today I was reminded of it when the CNN RSS feed threw this up. To sum up, nine northeastern US states are looking to pass an agreement to curb and then reduce pollution and greenhouse gas emissions from power plants. If you want to hear me ramble on you know what to do.

First of all, it does my heart good to watch States flex their regulatory muscles, to remind everyone that they still exist. It helps solidify the power for all States that would like to regulate something they see as a local problem, though some want to regulate different things.

Second, the article mentions that the US, President Bush, didn’t sign the Kyoto Protocol. I actually kind of understand that. I don’t think the US could have met the strict goals set in the KP without causing massive economic problems. However, I also think the current administration has done an awful job promoting good environmental practices and improvement. I wanted to see us not sign the KP, but commit to working to meet the goal as fast as we could. There are lots of relatively inexpensive ways we could do that: new efficient power plants, auto efficiencies, insulation in buildings, alternate power sources, etc.

Anyway, this agreement pretty much affects coal power plants the most. Coal is the most common power plant fuel used, and is the cheapest. The problem is it is also one of the dirtiest. A normal steam coal plant spews more radioactive material up it’s flue than any properly functioning US nuclear power plant. That doesn’t even mention sulfur for acid rain, soot, ash, smog components, carbon dioxide, etc. There are scrubbers and other technologies that clean up some of the pollution, but they can be expensive to add and run.

The thing is that coal is cheap and plentiful. It makes it an excellent power source, if it didn’t pollute so much. The answer seems simple, make coal pollute less. There are three major ways to do this; improve the efficiency, clean the fuel before you burn it, and clean the emissions before you release them. Current steam coal plants are about as efficient as you can make them. They currently wash the coal and other things to help clean it for steam plants. Steam coal plants already scrub the emissions to remove pollutants.

You may have noticed that I keep saying steam. Most of our coal plants run off the same technology that James Watt helped invent. We’ve extracted about all the efficiency, around 35%, and innovation we can out of the technology. Therefore, if we want a big change in efficiency, we need to look at new technology.

Stepping up to bat we have coal gasification technology. (Viewer for people without Office.) Basically the coal is heated in a special apparatus, similar to how oil is refined, and it is broken down into gasses and remnants. The remnants can be processed for use or disposal and the gasses can be cleaned in preparation for combustion. Cleaning at this point is more efficient and effective than post combustion. Then the gasses are burned in high efficiency heat recovery turbines. These systems are capable of passing 55% efficiency, and hold promise of improvements in pollution control, even CO2 capturing.

Recent administration initiatives have not promoted this technology. In fact they have relaxed regulations that made coal gasification (CG) more attractive as a design for new power plants and as incentive to replace older more polluting coal plants. I know that some CG plants are being planned as power companies are hedging their bets against future pollution controls, but many are just building regular old steam coal plants.

I’m glad to see some States taking an active roll in cleaning up some of this mess. Now it’s time to put the soap box away.