Did I hear COAL???

[Una_Persson]

*Originally posted by TwistofFate *
**as an aside, would the level of Solar/Hydro “green” methods be able to compensate with the downturn in Nuclear creation?

is it worth the time and effort to develop these to help compensate the level of coal energy production needed? **

The short answer is, hardly at all, depending on how much you want to pay for electricity. But then again, 2020 is a ways away still. If you can stand a $600 to $1000 a month electric bill at your current rate of consumption, then solar and wind will work for you.

The main issue comes down to cost. Solar is very expensive, wind is as well. It’s hard to see how wind can be made a whole lot more efficient, but solar definitely has some promise. I think more effort should be spent on developing these, certainly.

Hydro is cheap and great, but like I mentioned, we already have dammed everything we’re going to be able to in the US, and many environmentalists are now actively pushing to have dams removed. So hydro has apparently peaked. Great stuff, but it’s at the limit.

IMO, it’s always worth the time to explore ways to better use renewable energy sources. You see, many think that because my life’s work is with coal and coal power plant analysis that I am 100% pro-coal. Well, if someone produced a solar cell with a 90% efficiency, or fusion, or whatever, I would readily embrace it, even if I could no longer do my job.

[Sunspace]

Thanks, Anthracite, for a great post!

I live in a province that uses mostly nuclear, hydro and natural-gas for electricity generation; coal is a very minor item in the list.

I do pass a coal-fired power-plant regularly–but there’s a deal in the works for the state-owned utility (which was just privatized and broken up) to convert it to natural gas and sell it.

BTW, I remember reading a science-fiction novel about a small country in an unspecified location that had to rebuild its railways in the 21st century and chose advanced coal-powered steam locomotives, an innovative solution that had been overlooked by most other countries.

I got to thinking, we’ve tricked up the internal-combustion engine with computer controls and made it more efficient… is there any comparable work being done with external-combustion engines, either railway or road? Or are most people looking at fuel cells these days?

[Una_Persson]

*Originally posted by BunnyGirl *
OMG, what a great thread! Very interseting, Mr. Coal Man

Thank you. However, I prefer to be called Ms. Coal Woman…

**The original power plant here in Lansing was constructed with different color bricks, darker at the bottom and progressing lighter toward the top, to illustrate the coal combustion process. Its a pretty neat building, right downtown. The local Board of Water and Light is trying to find a buyer for - I guess it wasn’t functional or whatever anymore. No one wants to tear it down 'cause its a pretty cool building, right on the river, and has a lot of local history. **

That does sound cool, BunnyGirl. I never heard of that building - do you know what the name of the power plant was?

[Una_Persson]

*Originally posted by pluto *
**Adding processed fly ash (known as pozzalin) to concrete results in a stronger, more uniform finished product, but the most common reason for using it is because it reduces the amount of water required in the mix. The water in concrete doesn’t evaporate – it drives a chemical reaction known as curing. While curing, concrete gives off heat and the amount of heat given off limits the amount of concrete you can use at any one time. Very large projects (e.g., Grand Coulee Dam) would be much more costly and time-consuming without the addition of pozzalin to the concrete.

There are naturally occurring pozzalins, but, as Anthracite stated, fly ash is a very good source and is used almost exclusively nowadays.**

Great contribution, pluto, thank you. BTW, I read an article in Power once that in the early part of this century (err…last century, whatever) there was a very small coal plant in Connecticut that was built almost solely for producing fly ash for concrete use, using a high (about 25%) ash coal. From what I understand, they didn’t really add any tube surface to get steam and use for heating and power until nearly 2 years after it was first in operation!

[Una_Persson]

*Originally posted by Sunspace *
I got to thinking, we’ve tricked up the internal-combustion engine with computer controls and made it more efficient… is there any comparable work being done with external-combustion engines, either railway or road? Or are most people looking at fuel cells these days?

Well, I’ll add this interesting note. The newest high-tech trend in coal plants is in installing and using Neural Net Optimization Systems to improve the performance and emissions of the power plant. And in some cases, they do a very good job, where the software, hardware, sensors and instrumentation, and labor are paid back within one month!

It is amazing how little instrumentation and measurement goes on in a $200 Million coal plant. I am always just floored when the owners of a plant that large and that vital that costs that much to operate can’t tell me even what their coal burn rate is, which is the single most important variable in measuring the performance and emissions of a coal plant. With the installation of more and more measuring equipment and instruments and controls, huge efficiencies can be realized. And savings measured in millions of dollars per year. And cleaner air for all.

[Una_Persson]

*Originally posted by ASD *
**A state of the art coal plant will actually emit less carbon dioxide than a natural gas plant. Also, combined heat and power plants can cut down dramatically on carbon dioxide emissions (that’s when they use the steam generated to heat buildings rather than venting it or using cooling towers). **

While I agree that directly using the steam for heat is more efficient, I have to disagree about natural gas emitting less CO2 than a coal plant. If you mean in terms of equal electricity output, there are a few factors to consider:

Natural gas burns with a lower CO2 level than coal on a Btu basis. This can be verified by simple stoichiometric calculations. For example, in a unit I am evaluating which is cofiring Foidel Creek coal with Natural Gas, the results are:

lbm CO2 emitted /100 lbm coal : 230.84
lbm CO2 emitted /100 lbm gas : 266.66

with the coal at 11,300 Btu/lbm, and the gas at 22,737 Btu/lbm (1027.7 Btu/scf), we get the following:

CO2 production, lbm/MBtu:

Coal - 204.28 lbm/MBtu CO2
Gas - 117.25 lbm/MBtu CO2

so while they are close on a lbm basis, they are not on a Btu basis. And remember, the boiler doesn’t care about mass - it cares about Btu’s.

But this case was for coal steam versus gas steam plants. If one is comparing aeroderivative gas turbines, they have an even higher utilization efficiency, or heat rate than a coal plant does. So on a per-kW basis, a typical gas turbine will emit much less CO2 than a coal plant will. A top of the line coal plant will have a Net Unit Heat Rate of around 9000 Btu/kW*hr, which means for every 9000 Btu/hr (higher heating value basis) of coal which are burned, 1 kilowatt will be produced. This is approximately a 37.9% efficiency. And this is for an exceptional coal plant.

A gas turbine can be expected to have a Net Unit Heat Rate of about 7000 Btu/kW*hr (higher heating value basis), which means for every 7000 Btu/hr of gas burned, 1 kilowatt will be produced. This results in an efficiency of around 48.7%.

[Nukeman]

Wow, Anthracite, that first post has to be one of the longest on record. And the most fact - filled.

[sailor]

As usual, extremely good information from Anthracite. I have to give credit to dogzilla for learning from this thread but when asking “Did ya have to be so condescending at the beginning?” I would have to say yes, you were really asking for it. The OP was filled with assumptions and innuendo and was asking for a put down. If instead of Anthracite you would have got some responses from the conspiracy crowd, this thread would have taken a totally different direction. I commend you for being openminded and learning but if you read the OP you will see it was asking for a harsh response. I cannot blame Anthracite in the least.

At any rate, good and informative thread. I have some questions about electricity rates but I don’t want to hijack this thread so I should start a new one.

[ASD]

Ok–perhaps state of the art was a little overly optimistic. Experimental coal technologies (some of the pilot programs in the clean coal technologies program) using systems like fluidized pressurized beds and integrated gasification combined cycles can emit less CO2/kWh than exisitng natural gas plants. These are coal plants that are expected to see efficiencies of over 40% (I’d have to go back and check my thesis for the exact projections). Not exactly a fair comparison perhaps since methane plants are also improving, but the point is that research into cleaning up coal-based energy production is an important part of our energy strategy in my opinion. I would love to see us move more towards renewables–but until they become more reliable and cheaper we need to use cleaner coal technologies rather than relying on existing and aging plants that are inefficient.

[cornflakes]

I’ll second honkytonkwillie, Zette, et al. Thanks for your expertise.

The heavy bottom ash from the plant (about 20% of the ash produced) can be sold as abrasive material for sandblasting, and as aggregate. But normally it is not. When it is sold, it is often sold for free transport off the site.

So, roughly how dense is bottom ash and how rough of grit is this stuff? I’m looking for some blasting media that is lighter than sand, yet cheap. Maybe a better question would be what are the chances of someone driving up to a plant in Texas and driving away with a hundered pounds or so of this stuff. I assume that most plants would not allow this for safety reasons.

[Una_Persson]

*Originally posted by cornflakes *
**So, roughly how dense is bottom ash and how rough of grit is this stuff? I’m looking for some blasting media that is lighter than sand, yet cheap. Maybe a better question would be what are the chances of someone driving up to a plant in Texas and driving away with a hundered pounds or so of this stuff. I assume that most plants would not allow this for safety reasons. **

The density of bottom ash varies from coal to coal, but the typical number I use for calculations is 65 lbm/ft^3 (and 70 lbm/ft^3 for fly ash, if you are interested). It’s abrasiveness I can’t speak for in terms that would compare with sand.

Unfortunately, I really doubt (due to plant safety and security concerns) that they would allow people to just come on-site and remove bottom ash. So you are probably stuck looking for something else, I’m afraid.

[Duke]

Wow, Anthracite, I had no idea how much you’d earned your name. Thanks for the posts.

But I have two questions.

1. How safe is coal mining these days? I ask from a highly personal standpoint. My grandfather, who worked in a coal mine his whole life, died this April of lung cancer. My uncle, whom I am named after, died in a mining accident at the age of 21 (in 1965). He was my mom’s only brother. What is the total human cost of coal?

2. No matter how “non-polluting” coal is, the fact remains that it is still a fossil fuel, and a CO[sub]2[/sub] emitter. CO[sub]2[/sub] emissions are widely believed to contribute to the “greenhouse effect” and global warming. The European Union is hounding the US on its level of CO[sub]2[/sub] emissions and demanding a cut. Will the US be able to politically sustain the current level of use of coal in electricity generation, or will there have to be a shift to non-CO[sub]2[/sub] fuels?

Again, thanks for your thought-provoking discussion. I have to say that, because of my family experience, I am wary about the continued use of coal.

[Cartooniverse]

I’ve stood deep underground IN the Lackawanna Coal Mines…surrounded by Anthracite Coal. I now have a deeper appreciation for it. ( pardon the pun ). Ms. Anth, you are the best !!!

Cartooniverse

[sailor]

Duke, can you explain what you mean by “non CO2 fuels”?

[Una_Persson]

*Originally posted by Duke *
1. How safe is coal mining these days? I ask from a highly personal standpoint. My grandfather, who worked in a coal mine his whole life, died this April of lung cancer. My uncle, whom I am named after, died in a mining accident at the age of 21 (in 1965). He was my mom’s only brother. What is the total human cost of coal?

A good place to find all the information you would ever want on coal mining safety is the Mine Safety and Health Administration of the Department of Labor’s Website.

According to their site, there have been just 30 deaths due to all mining-realted causes as of 10/6/2000 for this year Coal Mine Fatalities, 2000 to date. These are almost all heavy machinery accidents, with a couple related to mine cave-ins or collapses. Black lung and other respiratory problems are no longer an issue, due to very stringent Government regulations on respiratory protection of coal miners and coal mine support workers.

I will leave you this website to give you more information, as it explains things a bit better than I can in the space provided. I will add this - of all the coal miners and persons in the industry I have ever met, none of them ever hated their job, or thought they were underpaid, or worked in an unsafe environment. But then again, this is the 1990’s, which is a far cry from the time of your grandfather and uncle.

2. No matter how “non-polluting” coal is, the fact remains that it is still a fossil fuel, and a CO[sub]2[/sub] emitter. CO[sub]2[/sub] emissions are widely believed to contribute to the “greenhouse effect” and global warming. The European Union is hounding the US on its level of CO[sub]2[/sub] emissions and demanding a cut. Will the US be able to politically sustain the current level of use of coal in electricity generation, or will there have to be a shift to non-CO[sub]2[/sub] fuels?

I mentioned above that CO2 emissions were the one thing that coal utilization could not avoid, regardless of how many other emissions controls one places on the plant. The answer to your question is complex, as it is almost entirely a political one at this point in time. My guess is coal consumption will stay constant or slowly decline over the next 10 years (possibly to as low as 45% of the total energy production over the year), being replaced somewhat by natural gas. But I, and some other energy analysts I know, feel very strongly that natural gas prices will simply be too high within 12 years due to depletion. And if fusion energy does not come about, solar does not have a remarkable breakthrough in technology, and nuclear does not re-enter public favor and plants continue closing, then we will be steadily increasing coal combustion once again.

[Arjuna34]

Thanks for the safety info, Anthracite (as well as the extremely informative posts before it!) My grandfather was also killed in a coal mine, in western Virginia when the mine caved in.

Arjuna34

[RM_Mentock]

My father worked down in the coal mines of Wyoming when he was young, alongside my grandfather and great uncles. I tell my kids that we were the envy of the neighborhood because we had coal-fired TVs, while everybody else only had wood-burning TVs.

This DOE site projects the percentage of electricity generation from natural gas will increase, while that from coal will decrease over the next twenty years. “Generation from both natural gas and coal is projected to increase through 2020 to meet growing demand for electricity and offset the decline in nuclear power; however, the share of coal generation declines through 2020 because assumptions about electricity industry restructuring, such as higher cost of capital and shorter financial life of plants, favor the less capital-intensive and more efficient natural gas generation technologies.”

[Dogzilla]

*Originally posted by Anthracite *
**

No, I most certainly did not have to be, and I apologize to you. I posted that I was sick in my first response, and I will fall back on that as my only excuse for why I was in a bad mood last night. Once again, I am sorry.

**

2. But the major reason is the sulfur content, as the Clean Air Act Amendments of 1990 caused most all coal plants East of the Mississippi to consider switching to low-sulfur Wyoming and Montana coal to reduce SO2 emissions (sulfur dioxide, a principal component of acid rain). Coal commonly mined in the East can typically have sulfur contents ranging from 1 to 3 percent, while coal mined in Wyoming and Montana can range from 0.2 to 0.5 percent typically.
   **

Thanks and I forgive you now! And I hope you’re feeling a lot better, too! I can be pretty grouchy when I feel crappy too so I completely understand.

Now that you (and someone else) mention it, I do remember something from my environmental geology class about the sulfur content in the WVA coal. I went to college in the Appalachian foothills in SE Ohio – two minutes out of town and you could clearly see the tragic effects of the coal industry (esp. the now-defunct – I think – practice of strip mining) all over the place. There were many grassroots organizations formed to try and assist these people.

Anyway, thanks to all for a lively and informative discussion – I’m learning loads!

[lemartel]

Since coal is the topic I have a question. I heard that Clinton set aside a large portion of a western state, Utah I think, as a national monument a year or so ago. This site was supposed to have a large deposit of coal under it that could not now be mined because of the monument designation. Is this true and does it affect the numbers stated above in any way? The context I heard this in said something about the only other comparable site in the world was in Riady controlled Indonesia. Do you or anyone else know the straight dope on this?

[Duke]

Anthracite:

Thanks kindly for the information. I guess coal mining has become safer in the modern era, though 30 deaths to the first ten months of the year is still a bit troubling. BTW my uncle died in a strip-mining accident; not the deep-pit he and my grandfather usually worked in, but obviously still a dangerous business in the 1960’s.

A bit more about the EU, UK and coal–it goes without saying that the UK government over the last 25 years has been awful to the coal industry here. The coal industry is pretty much no more in England–there are only two deep pits still operational at anything like near capacity (both in Yorkshire). Wales still has some mining (many of the old miners, especially in northeast PA, were from the Welsh valleys).

On top of that, the EU has been fighting the US tooth and nail over CO[sub]2[/sub] emissions, and one of the sore points seems specifically to be the US’s reliance on coal-powered electricity generation. Gore is on the record as wanting to “negotiate” with the EU on emissions, so that could spell problems for the US coal industry if he’s elected.

Again, thanks for the info, Anthracite.