Virtual Tour of a Coal Fueled Electric Power Plant

While I'm not a proponent of coal fired electric generation, I did find this video an interesting overview of the process. After you've watched the video, you should go to the Union of Concerned Scientists website to get some additional information.

[youtube]http://www.youtube.com/watch?v=e_CcrgKLyzc[/youtube]

Where do we find the video?

[EDIT] OK, i see a link to YouTube when I'm doing a reply with a quote, but I don't see the link when looking at the posted message - just a big blank space.

indyflick said:

While I'm not a proponent of coal fired electric generation, I did find this video an interesting overview of the process. After you've watched the video, you should go to the Union of Concerned Scientists website to get some additional information.

[youtube]http://www.youtube.com/watch?v=e_CcrgKLyzc[/youtube]

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Interesting and informative. It also shows how the scrubbers work that reduce the particulate emissions. I was hoping to see some tours of their other generating plants but I couldn't find any on youtube.

I haven't looked at the video yet, but I've worked enough with coal-fired power plants to know that scrubbers are to remove sulfur oxides from the flue gas, not particulates. Bag houses or electrostatic precipitators are used for particulate removal. (And at some plants, catalytic reduction is used to remove nitrogen oxides.)

I hope that video didn't really say that scrubbers are used for particulate removal, as it would call other information into question.

Regards, JEff

johnr said:

Interesting and informative. It also shows how the scrubbers work that reduce the particulate emissions. I was hoping to see some tours of their other generating plants but I couldn't find any on youtube.

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Yodrak said:

I haven't looked at the video yet, but I've worked enough with coal-fired power plants to know that scrubbers are to remove sulfur oxides from the flue gas, not particulates. Bag houses or electrostatic precipitators are used for particulate removal. (And at some plants, catalytic reduction is used to remove nitrogen oxides.)

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Thanks for that info. My mistake. Somehow when I heard sulfur oxides in the video I thought particulates.

Yodrak said:

I haven't looked at the video yet, but I've worked enough with coal-fired power plants to know that scrubbers are to remove sulfur oxides from the flue gas, not particulates. Bag houses or electrostatic precipitators are used for particulate removal. (And at some plants, catalytic reduction is used to remove nitrogen oxides.)

I hope that video didn't really say that scrubbers are used for particulate removal, as it would call other information into question.

Regards, JEff

johnr said:

Interesting and informative. It also shows how the scrubbers work that reduce the particulate emissions. I was hoping to see some tours of their other generating plants but I couldn't find any on youtube.

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Yodrak/JEff, that is not correct. In fact, there are several types of scrubbers designed specifically for controlling particulates. The specific type depends on the characteristics of the process stream. There are several wet scrubbers, such as venturi scrubbers, that remove particulates from process streams quite efficiently. In fact, they are especially efficient for removing larger sized particulates (such as fly ash). Specific to this video, it states that the fly ash is removed by a "mechanical process" (i.e., venturi scrubber or even a packed bed scrubber), while the sulfur dioxide is removed by a "chemical process" (i.e. caustic scrubber - reaction with caustic solution, lime). It would be plausible to have a single wet scrubber that incorporates both principles to control both particulates and sulfur dioxide, as appears to be the case in the video.

Using baghouses to control particulates from a process process stream with much of a moisture content would not be advisable. While I don't work with coal-fired electric power plants, I do work with various air pollution control equipment.

The venturi scrubber that you describe for particulate removal is not commonly used on coal-fired power plants. I've never seen one although, as I said, I have not yet had a chance to view this particular video. If the plant in the video uses a venturi scrubber for particulate removal it's a rarity.

I note that bag houses are a "mechanical process" for particulate removal, and that bag houses are installed upstream of the SOx scrubbers. Electrostatic precipitators, the most common type of particulate removal equipment, are also installed upstream of the scrubbers.

Agreed SOx scrubbing is a chemical process.

Agreed also that a single unit for removing both particulate and S0x is feasible, but to date has not been very successful in practice for coal-fired power plants - high maintenance and low removal efficiency relative to two separate units dedicated to particualte removal and SOx removal, respectively. Again a rarity if the power plant in the video uses such a system.

Not many coal-fired power plants have been constructed in the USA in the last few decades. Some, yes, but not many. As a practical matter most of the coal-fired power plants in the USA were originally constructed with electrostatic precipitators as the only form of environmental control. Most if not all of those precipitators have been upgraded or replaced with bag houses as environmental regulations have become more strict. When SOx regulations came into effect many plants switched to burning coals that have a naturally low sulfur content, some have installed scrubbers, some have done both, and some plants are only now making plans to install scrubbers. The add-on scrubbers are installed downstream of the particulate removal equipment.

JPVLeaf said:

Yodrak/JEff, that is not correct. In fact, there are several types of scrubbers designed specifically for controlling particulates. The specific type depends on the characteristics of the process stream. There are several wet scrubbers, such as venturi scrubbers, that remove particulates from process streams quite efficiently. In fact, they are especially efficient for removing larger sized particulates (such as fly ash). Specific to this video, it states that the fly ash is removed by a "mechanical process" (i.e., venturi scrubber or even a packed bed scrubber), while the sulfur dioxide is removed by a "chemical process" (i.e. caustic scrubber - reaction with caustic solution, lime). It would be plausible to have a single wet scrubber that incorporates both principles to control both particulates and sulfur dioxide, as appears to be the case in the video.

Using baghouses to control particulates from a process process stream with much of a moisture content would not be advisable. While I don't work with coal-fired electric power plants, I do work with various air pollution control equipment.

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Yodrak said:

I haven't looked at the video yet, but I've worked enough with coal-fired power plants to know that scrubbers are to remove sulfur oxides from the flue gas, not particulates.

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Yodrak said:

I hope that video didn't really say that scrubbers are used for particulate removal, as it would call other information into question.

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IIRC, this thread is about the video that was posted by indyflick. As a reminder, the 9-minute video was introduced as a general overview of typical coal fired power plants operated by First Energy. No more, no less. It would help if you would actually watch the video before you question the appropriateness of its content.

Initially, you called out another poster for basically repeating what was in the video. Instead, you stated that 'scrubbers are not used for particulate removal' (paraphrased). That is what I called you on because, as worded, the comment is not true. Based on your last post, I think what you meant to say the first time around is that based on the coal fired power plants you have had experience with, you have not seen scrubbers being used for particulate control. Two different things.

Yodrak said:

The venturi scrubber that you describe for particulate removal is not commonly used on coal-fired power plants. I've never seen one although, as I said, I have not yet had a chance to view this particular video. If the plant in the video uses a venturi scrubber for particulate removal it's a rarity.

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In your last post, you say that venturi scrubbers "are not commonly used" for particulate removal and "is a rarity" (paraphrased). This might be the case, but I was merely describing a specific type of scrubber that could be used for the type of process stream described in the video. It was an example of a dual ACP device that could control both sulfur dioxide and particulates. No more, no less. (Also, you then repeat that you still hadn't watched the 9-min. primer video.)

There are points in your last post that I would agree with, and others that I would not agree with. Simple Google searches would point those out. But, again, none of that has anything to do with what's in the 9-minute primer video. So I'll leave it at that.

There are complexities and subtleties regarding design and choice of APC that I don't think either one of us has a need to discuss on an EV forum.

I suggest we drop it and get back to talking about the Leaf ....

[youtube]http://www.youtube.com/watch?v=Fmkb1ito3K0[/youtube]

I've watched the video, and I think it is a very good overview of a modern coal-fired power plant. It strikes a very good balance between simplicity and detail, the level of simplicty is appropriate for an introduction to the operation of a highly complex facility.

Having watched the presentation of the flue gas clean-up systems I can understand how there can be some confusion over how the clean-up processes work, in large part because the video presents the three clean-up systems in the reverse order how the clean-up process actually works. Going from the boiler to the stack, the flue gas first goes through the SCR process for nitrogen oxide (NOx) removal, then through an electrostatic precipitator for particulate removal, and lastly through the scrubber for sulfur dioxide (SO2) removal.

I'm impressed that the scrubber technology used at this particular plant produces a gypsum product that can be used to make wallboard. That would not be possible if the scrubber was also doing particulate removal. Consumers are used to, and want, white wallboard. It would be a hard sell to get them to accept grey wallboard, if wallboard could even be made using gypsum that contains fly ash.

I'm also impressed that this plant also has found a use for its fly ash. Fly ash does have very good pozolonic properties and makes a good admix for concrete for certain purposes, but its use is controversial due to fears that some of the constituants of the fly ash can leach out of the concrete into the environment.

Bottom line, the video shows that this plant does use 3 sparate and distinct processes for cleaning up its flue gas - SCR for NOx, electrostatic precipitator for particulates, and scrubber for SO2 - as I speculated. More important, we see what makes the emissions from a coal-fired power plant lower than the emissions from ICE automobiles. Not zero emissions, for sure, but less emissions than the ICE automobiles that EVs replace. A step in the right direction.

JPVLeaf said:

Yodrak said:

I haven't looked at the video yet, but I've worked enough with coal-fired power plants to know that scrubbers are to remove sulfur oxides from the flue gas, not particulates.

Click to expand...

Yodrak said:

I hope that video didn't really say that scrubbers are used for particulate removal, as it would call other information into question.

Click to expand...

IIRC, this thread is about the video that was posted by indyflick. As a reminder, the 9-minute video was introduced as a general overview of typical coal fired power plants operated by First Energy. No more, no less. It would help if you would actually watch the video before you question the appropriateness of its content.

Initially, you called out another poster for basically repeating what was in the video. Instead, you stated that 'scrubbers are not used for particulate removal' (paraphrased). That is what I called you on because, as worded, the comment is not true. Based on your last post, I think what you meant to say the first time around is that based on the coal fired power plants you have had experience with, you have not seen scrubbers being used for particulate control. Two different things.

Yodrak said:

The venturi scrubber that you describe for particulate removal is not commonly used on coal-fired power plants. I've never seen one although, as I said, I have not yet had a chance to view this particular video. If the plant in the video uses a venturi scrubber for particulate removal it's a rarity.

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