Ohio State develops clean coal technology | Hacker News Reader

Ohio State develops clean coal technology

osu.edu

72 pointspetercooper61 comments

As a person whose roots in Appalachia (West Virginia/southwest Virginia border) go back a long ways, I'd love to see someone talk about the other dirty aspect of coal: the way its mined. I get the feeling that a very large percentage of the population has no idea that they are literally blowing the tops off of mountains throughout Appalachia to get this stuff. Anyone who thinks this is acceptable has proably never been to a site where it has been done(it looks like the surface of the moon), or lived near a creek which gets filled in with the massive amounts of runoff from it.

I wish they would go after coal the old fashioned way, but it is more expensive and more dangerous that way.

Right, in correct terms there is no such thing as 'clean coal'

Using these definitions that include the entirety of the process, no energy is clean energy except for Sunlight + 6CO2 + 6H2O -> C6H1206 +6O2.

Even solar power will have something "dirty" along the chain somewhere.

The closest we can get is to "offset" the dirtiness.

Ditto for nuclear.

Had my fair share of discussion with neckbeards on the Internet touting how incredibly clean nuclear energy is. You know, as long as you leave out the mining (radon emissions being one of the commonly known issues, the chemicals involved in mining not as well known; furthermore, many mines don't get any cleanup after decommission) and the storage of the nuclear waste (which is simply an unsolved problem). But hey, less CO2, right?

Well, what is the lesser of all evils? We need lots of energy, and it's only going to get worse as India, China, and the rest of the world come online.

If you're into that sort of thing, just look through my comment history, it's not that far down. I'm pretty much done with that discussion.

Just for the sake of urgency, this discussion is already behind the curve.

China already consumes almost as much coal as the rest of the world combined:

http://www.eia.gov/todayinenergy/detail.cfm?id=9751

What's the logic there? That nations other than china shouldn't bother with (or without) new coal technology and energy policy because it is only a "small contribution?".

That argument gets pretty much everyone who isn't the USA or China off the hook. Luxembourg and Botswana should just pollute as much as they want? That's just dumb. Energy choices are important everywhere; it just happens that the only forums available for enacting this policy are in nations with diverse sizes. You still need to do it everywhere.

Actually no, my point is that we should not be looking at this as some future event.

Our coal problems are not on the horizon, they're substantial problems now. I don't care if there's additional room for growth in the coal power plant market in Africa, current coal consumption is more than sufficient to warrant action.

Given all the production that's being sourced from China, we should also view it as our problem and not merely China's, in terms of its cause.

How convenient, to dodge the cost of e.g. scrubber technology, by moving production to where it isn't required.

Meaning, by the way, for contaminants such as mercury and other heavy metals. IMO, CO2 sequestration is pure folly.

Things to come -

http://www.chinahush.com/2009/10/21/amazing-pictures-polluti...

A very striking collection of photos. Was the industrial revolution in America and Britain ever this bad? I've heard stories about people in the 1950s in the US (can't remember where, but I believe it was in Utah) having respiratory problems while walking down a street because of the sulphuric acid fumes coming from a nearby factory, praying for a car to stop and give them a ride so they wouldn't die.

Storing nuclear waste is a very technically solvable problem. Politically, it is difficult to solve because most people are terrified of it and have "not in my backyard" syndrome.

The dangerous radiation is simply not going to be around for 25,000 years. We need to be really really sure that the harmful stuff is safe for 100-200 years. That doesn't seem hard to me considering a couple million people a day are driving over bridges into NYC that are 100+ years old. Steel and concrete last a pretty long time. Water absorbs radiation pretty well. Combine it all with a hole deep into a dry dessert, and you are fine.

"Storing nuclear waste is a very technically solvable problem. Politically, it is difficult to solve because most people are terrified of it and have "not in my backyard" syndrome."

There are very good reasons why people don't want nuclear waste in their back yard: 1) lack of trust in the people who build and maintain the containment units, 2) evidence of massive screwups at nuclear facilities that led to the likes of Chernobyl and Fukushima, not to mention smaller screwups, lies, and coverups of shoddy maintenance and safety issues at other nuclear facilities.

The technical issues of nuclear waste containment might be solved, but the social issues related to who stores the waste have not. There are no guarantees that the waste will in fact be stored properly, and that the people who store the waste will be competent enough to do so, nor that they will refrain from cutting corners on safety so they can make a quick buck, earn some kickbacks, or score some political points.

Water absorbs radiation pretty well.

Water absorbs radiation incredibly well. You can swim in a spent-fuel pool, so long as you don't go too deep.

http://what-if.xkcd.com/29/

The fuel could be reused and reduce the amount of of waste. I believe the reason it is not is the threat politicians have been lead to believe that it can also be used to build weapons.

Where would you rather store the waste products from power generation? In casks at nuclear plants, or in your lungs?

Red. Herring.

This is just one of the worst disasters: http://en.wikipedia.org/wiki/Buffalo_Creek_Flood

Plenty of other "accidents" large and small.

"Additionally, the chair of the Citizen's Commission, Norman Williams, the Deputy Director of the West Virginia Department of Natural Resources, called publicly and in testimony before the legislature for the outlawing of coal strip mining throughout the state. He testified that strip mining could not exist as a profit making industry unless it is allowed by the state to pass on the costs of environmental damage to the private landowner or the public."

This is the key point of coal, and really all forms of fossil fuel harvesting. The current U.S. (and India/China) regulatory environment inevitably passes the negative externalities of extracting and consuming the fuels onto the citizens of said countries. (if you factor in carbon, then the citizens of the world)

In Eastern Europe there are certainly numerous environmental consequences to the coal mining. One that isn't that grave but makes for a lasting impression is the huge spoil tips (e.g., http://imgur.com/a/aB1EJ) that can often burn slowly inside.

There is a Harvard study that analyses this issue. The cost is enormous: http://solar.gwu.edu/index_files/Resources_files/epstein_ful... (takeaway on page 91)

The public health burden in Appalachia alone is estimated at $75 billion per year.

Whenever you seed the phrase 'clean coal' check for you wallet. There are many irreducible problems with coal.

First, you've got to get it out of the ground. The most common ways of doing that are strip mining and mountain top removal mining. Both not only destroy the area actually minded but produce enormous amounts of liquid and solid waste (coal slurry and fly ash are the worst) that destroy whatever environment they are deposited into.

Second, however you cut it, the fundamental chemical reaction is going to be CxHxOx + O2 => CO2. There is no way to avoid producing carbon dioxide if you want and exothermic reaction. So you get carbon dioxide capture schemes. The problem is once you capture the carbon dioxide no one has any idea what to do with. There are vague notions that we can pump it underground, but pilot projects in this area have been dismal failures both because of a lack of confidence that the CO2 will remain buried and because of the high energy costs in burying the CO2.

Third, aside from CO2, coal has a variety of other nasty constituents: mercury, uranium, thorium, arsenic among others.

> Third, aside from CO2, coal has a variety of other nasty constituents: mercury, uranium, thorium, arsenic among others.

How high is the radiological pollution from coal I wonder? All that stuff gets turned to ash and spread around by wind and now it will be some kind of slurry I guess. Still have to do something with it.

"Coal power stations, for example, expose the public to nuclear radiation, because coal ash typically contains uranium. Indeed, according to a paper published in the journal Science, people in America living near coal-fired power stations are exposed to higher radiation doses than those living near nuclear power plants."

"–People in America living near coal-fired power stations are exposed to higher radiation doses than those living near nuclear power plants. Source: McBride et al. (1978). Uranium and thorium have concentrations of roughly 1 ppm and 2 ppm respectively in coal. Further reading: gabe.web.psi.ch/research/ra/ra res.html, www.physics.ohio-state.edu/~wilkins/energy/Companion/E20.12.pdf.xpdf."

http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_16...

http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_17...

When I hear a comparison made in that manner my fraud antenna goes up. 'Higher radiation doses than those living near nuclear power plants!' Is the sort of breathless thing you can say without considering that people living near nuclear power plants might not have much of a radiation dose to begin with?

Clean energy begins with honest conversations about the cost/benefit of each type of energy.

I don't think I understand your objection. The comparison between coal and nuclear power is made because there is a public perception that living near a nuclear plant is dangerous, while coal plants are ignored.

The electricity I'm using to write this was in all likelihood generated by the local coal power plant (though there is some wind and hydro generation nearby); I wish they'd replace it with nuclear.

...people living near nuclear power plants might not have much of a radiation dose to begin with?

That's exactly the point.

The extra dosage for living near a coal power plant is really low - about 2% of a chest x-ray per year. The extra dosage for living near a nuclear power plant is nearly non-existent at a third of that.

The chemical effects of the pollutants in fly ash are a far bigger concern than the radiological effects.

Edit: Neat chart (http://xkcd.com/radiation/)

Second, however you cut it, the fundamental chemical reaction is going to be CxHxOx + O2 => CO2.

I thought most fuels were hydrocarbons (CxHx - e.g. propane is C3H8, methane is CH4, benzene is C6H6), not carbohydrates (CxHxOx).

There is no way to avoid producing carbon dioxide if you want [an] exothermic reaction.

I'm not a chemist, so forgive this question if it is naive: is there no catalyst or chemical process that can completely strip the carbon from the hydrogen, oxidize the hydrogen, and leave only carbon and water?

The shorter carbon chain molecules tend to be hydrocarbons, but as they get longer and longer other elements tend to be incorporated.

Take a look at an example chemical structure for coal from Wikipedia: http://en.wikipedia.org/wiki/File:Struktura_chemiczna_w%C4%9...

Anyway you are going to need something to bind to the carbon. Pure carbon allotropes (graphite, diamond, buckyballs, etc.) are extremely energetically disfavored as compared to CO2 at normal pressures. You could use fluorine instead of oxygen, but tetrafluoromethane (CF4) has a greenhouse gas potential 6000 times that of CO2, and is fairly poisonous to boot.

It's sad, to me, that so much research continues to go into fossil fuels. We are so close to cost parity from renewable sources of energy; and, in some cases, it's already cheaper to use solar or wind energy, if you amortize over a long enough period (solar panels can last up to 50 years, with very little maintenance). Why do we have to dig up and burn every ounce of coal and oil and natural gas? Why not divert all of that effort, money, and time, into something that will last until the death of our sun? In a few years time, we'll all have cheaper power, and far fewer concerns about the destructive means by which the fuel is obtained.

Even with zero emission (though not zero waste) coal power generation, there's still tremendous environmental and human life impact from its mining. There are 30 coal mining deaths per year in the US alone (which has more stringent safety standards and more modern equipment than almost anywhere else in the world that mines coal).

I mean, this is cool and all. But, it doesn't solve the problem of coal being a limited resource that is dangerous and ecologically destructive to obtain.

This sounds downright revolutionary. Could someone with domain knowledge comment if this is really such a new thing?

The press release says,

>In chemical looping, the coal isn't burned with fire, but instead chemically combusted in a sealed chamber so that it doesn't pollute the air. A second combustion unit in the lab does the same thing with coal-derived syngas, and both produce 25 thermal kilowatts of energy.

How much coal does it take to produce those 25 kW? You'd think efficiency is what most readers would want to hear about at this point because everything else sounds pretty great.

A page linked [1] from the press release states that

>New technologies that use fossil fuels should not raise the cost of electricity more than 35 percent, while still capturing more than 90 percent of the resulting carbon dioxide.

but it is unclear if this is mostly due to the price of extra coal or the equipment itself.

[1] http://researchnews.osu.edu/archive/looping203.htm

You'd think efficiency is what most readers would want to hear about at this point because everything else sounds pretty great.

It's necessarily less efficient than coal power without CO2 capture. From these slides [1] they estimate 35%, vs. 39% for a conventional coal plant, and 29% for a different type of CO2 capture (post-combustion CO2 scrubbing with monoethanolamine [MEA]).

...but it is unclear if this is mostly due to the price of extra coal or the equipment itself.

Mostly equipment/capital [1].

[1] http://www.netl.doe.gov/publications/proceedings/12/co2captu...

coal isn't burned with fire, but instead chemically combusted

I'd like some clarification on the difference between "fire" and "chemical combustion"

One definition of "fire" demands "oxygen from the air":

https://www.google.com/search?q=define+fire&oq=define+fi...

The fuel here doesn't react with air, but with a solid oxidiser (Fe2O3). It's a solid-solid reaction, whose products are gases (CO2 and H2O). Just like a solid-fuel rocket.

And how is CO2 form Fe2O3 different than CO2 from the air? Is it just that it is easy to capture? Then what?

It's not different, but it's a pure gas and not mixed with a ton of nitrogen that air combustion exhaust would be. That makes it trivial to capture (literally just pump it through a compressor into a tank).

One important point, though, is that the sequestration problem is not actually addressed here. This just gets you conveniently-produced tanks of CO2 (or crates of dry ice, whatever). What you do with that to keep it out of the atmosphere is still an open problem.

Thank you, now it makes some sense. These press releases are next to useless.

It unclear where all of the carbon dioxide goes after they capture it. Does the process actually use the carbon dioxide for a second reaction? Or do they just put it in a tank somewhere? If it's the later, this would be difficult to do at scale.

It's meant to be injected underground.

But given coal has perhaps 500 kg/m^3 of carbon while pure CO2 at ambient pressure has about 0.5 kg/m^3. A thousand fold difference.

How are you going to dig something up from the ground, expand it thousand fold and put it back in to the same hole?

I don't understand this carbon storage business. Clearly coal is the best carbon storage method by far, and it doesn't cost anything as it's already stored.

You can also store it in the holes that you took natural gas out of. I'm not aware of it being done on any large scale, but it's been talked about a lot.

It would be pressurized before storage. However, to reach 500kg/m^3 it looks like it will be close to becoming a liquid: http://www.wolframalpha.com/share/clip?f=d41d8cd98f00b204e98...

The critical point is at 7.4 MPa (74 bars) and 304 K (30 C) - there the density is 470 kg/m^3.

Here's the phase diagram. http://www.wolframalpha.com/input/?i=co2+critical+point&...

According to this http://web.anl.gov/PCS/acsfuel/preprint%20archive/Files/45_4... the pressures in depleted natural gas wells are 20-40 bars so it's not as bad as I expected.

Never seen any numbers so had to go look.

I think once you consider the water vapor that is also generated from burning natural gas, storing the resultant CO2 in the same space might actually be possible. I suppose I could do an actual calculation based on the molecular weight of H20 and reading up on the combustion stoichiometry of methane et al., but I'm not a chemist by any stretch of the word, and I've got other things to do :).

1 CH_4 + 2 O_2 -> 1 CO_2 + 2H_2O

So the amount of CH4 and CO2 is the same in number of molecules, which also means they are the same volume of gas (at low pressures). Of course the mass of CO2 is about three fold but that doesn't mean much.

There's very little you can do with the captured CO2. It's a pretty inert gas that can only be broken up and reused for a second reaction if you add energy which is contrary to the goal of creating electricity. So the only option is storage, which is a bit of a problem at scale. There are some test power plants in germany that try this, but the basic idea is to collect the CO2 and push it into old, used natural gas fields. However, obviously nobody really feels safe sitting on a giant bubble of CO2...

I generally store captured CO2 in homebrew. Clean. Cheap. Delicious.

Great idea. Does it scale?

Uh, temporary?

Well, some of these tripels only seem to get better with age, so extrapolating from that, we can assume that storing it forever will produce an infinitely tasty beverage. Drinking it will, of course, truncate the 'forever' timeline, thus making it less than 'infinitely tasty', so the only way to preserve the extreme flavor is to never open it, thus: sequestered.

waves hands

Sell it to PepsiCo!

Sounds like a variation on coal gasification: http://en.wikipedia.org/wiki/Coal_gasification

The article is a bit scant on details like by-products or the emissions from the combustion of the syngas in the secondary combustion process.

And, whenever I hear "Clean Coal" I feel like someone is trying too hard to sell me on something. This whole article reads like it was written by the coal industry.

You better believe this research was funded by the coal industry. And my god, the way it is written, I would be embarrassed to be an OSU alumni. I realize that all public research universities do this crap, including my alma mater Virginia Tech, but I hate it when they do.

Seriously, the tone of the article reeks of political campaigning. With Virginia and Ohio, two coal producing states that are now both swing states, you can bet that coal will continue to get tons of attention from the Federal government.

Clean coal is a lie. The byproducts of coal usage are stored in gigantic ash ponds. In 2008, one such pond ruptured and spread 5.4 million cubic yards of waste containing mercury, arsenic, lead, and thallium (amongst other things) all over eastern Tennessee.

https://www.nytimes.com/2008/12/27/us/27sludge.html?_r=0

So just to play devil's advocate: there's already a bunch of mined coal out there, and you'd better believe it's going to get used by someone to create energy. Extracting that energy can either release CO2 into the atmosphere and contribute to total ecosystem collapse, or not. The only other alternative is that, somehow, existing coal doesn't get used at all, and if you could concoct a scenario where that's plausible, I'd be very impressed.

When it comes to climate change we're talking about irreparable harm to the planet, mass extinction, and a serious existential threat to our species. Without minimizing the social and environmental problems created by coal mining, I think it's correct to say they are lesser problems than those posed by climate change.

I absolutely agree that in general, civilization can do better than digging shit out of the ground and burning it, and I think the long term solution is wind, solar, geothermal, tidal, and so on. Unfortunately we don't have time to wait for a perfect solution, and we have huge amounts of fossil fuel reserves that, if they're all conventionally burned, will kill us all. So what can we do?

The stocks of mined but unused coal are pretty small. It's very bulky and so expensive to store. Even oil doesn't have all that much storage, which is why when the market went into high contango traders had to rent oil tankers to store the oil they were buying on the spot market.

As for CO2, the method the article is talking about makes it convenient to capture CO2 (at an energy cost) but transporting and storing it once captured are far more difficult problems.

Gee I wonder who funded this research? Hrmm....

Mining coal is hugely destructive, even if we take a logical leap and just believe that this really is "clean coal" for creating power.

It's a waste of time. Solar, Wind, Geothermal and intelligent Hydro are the way forward. Everything else is just a bad compromise.

This will probably be a big help for China if it is cheap enough given their use of coal. Coal is what we used to get to our current status and it will be what everyone else uses unless we come up with something cheaper and just as constant.

...but it's still coal and coal is dirty.

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