Pub #brownchem: @alpha137

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*** lizzk (gloworm4@175-180-214.ipt.aol.com) has joined channel #brownchem

alpha137: hello

lizzk: hello

alpha137: I had lunch with a chem engineer at Brown who works with coal.

alpha137: I learned a few things.

lizzk: what?

alpha137: As we said, coal is a complicate mixture of things. It has a lot of hydrigen in it. Coal is, perhaps, mostly a hydrocarbon.

lizzk: so more hydrocarbon that the normal carbon you think of

alpha137: Yes.

lizzk: that = than

alpha137: Furthermore, when coal is burned it leaves an ash.

lizzk: oh

alpha137: Called flyash I think.

lizzk: what is flyash made of?

alpha137: This ash is very fine, in the tens of micron range.

lizzk: wow

alpha137: I think the flyash must be the residual inorganic stuff left over after most everything has burned.

lizzk: I see, would n't that be dangerous if it was inhaled

alpha137: The flyash has a commercial use.

alpha137: Flyash is not good to breath.

lizzk: What is the commercial use?

alpha137: Odd you should ask.

alpha137: It is used in cement.

lizzk: why?

lizzk: nevermind my last comment

alpha137: The flyash strengthens concrete!

lizzk: really, thats strange, how did they discover that!

alpha137: A coal fired electrical generation plant is required to remove sulfur dioxide and the fly ash.

lizzk: At least it is being put to good use

alpha137: I am not sure how the beneficial properties of flyash were discovered. Probably by just trying out different things to find some use for the stuff.

lizzk: ok

alpha137: This is an intresting lesson, or model of how an environmental problem can be mitigated somewhat to the benefit of the public and industry.

lizzk: yes

alpha137: But, there are costs that have an impact on this use of flyash.

lizzk: Could they throw in some of the other bad stuff that comes with coal (like So_x) into the concrete too?

lizzk: Is it very expensive to use flyash?

alpha137: I think that the removal of sulfur from coal, as our text says, produces loads of CaSO_4. I am not sure what this would do to concrete, but I suspect that it does no good otherwise my ChE friend would have mentioned it.

lizzk: ok, thats too bad

alpha137: It remains to be seen is CaSO_4 would strength concreted.

lizzk: you never know

alpha137: It sounded to me that transportation costs were enough to make the use of flyash in concrete uneconomical.

lizzk: thats not good,

lizzk: and there is no easy solution to that

alpha137: For example, in New England, and Boston in particular, there is a lot of construction going on. The powerplants are close by and virtually all the flyash produced is being used.

lizzk: I see, but in say the Midwest, if not a lot of concrete is being made, then not a lot of the flyash will be usde

lizzk: used = usde

alpha137: The flyash is sold by the electric utilities to the concrete companies.

lizzk: i see

alpha137: Right, in the Midwest there is a problem. The flyash is not being used because there is not such a demand for concrete. Trucking the flyash product elsewhere is apparently too costly.

lizzk: well, it makes sense, what do they do with it instead??

alpha137: I am not sure. The flyash has to be disposed of and probably is treated as a toxic waste-but not all that toxic.

lizzk: I see

alpha137: If you think about it, there are a number of economic and health issues that are connected in this one thing.

lizzk: yes

alpha137: Just what can be done must depend on the relative costs of all these variables. Including health costs, disposal, etc.

lizzk: Is their flyash in the air right now that I could be breathing in, or is it contained in the plants?

lizzk: their = there

alpha137: I am not sure, but the Clean Air Act has limits on particulate matter in the air. This is monitored by the State. Also, as research progressed it was realized that particle size was important.

alpha137: Therefore, a new standard was developed called PM10. This has to do with particle size 10 microns or less.

lizzk: ok, and flyash is made of small particles.

alpha137: Right.

lizzk: Ok, what are the health costs, do they have any estimates yet, or is it too small of a problem for people to spend much time on?

alpha137: Small particles get deep into the lungs where they do more damage. Also important is the chemical constitution of the particles-and perhaps even their shape.

alpha137: These health costs are great, but it is difficult to make quantitative measures. How might you begin to do this?

lizzk: ok, but of flyash?

lizzk: Try to determine how many people a year get lung cancer etc, from this particulate matter, then how much, on average does a case of lung cancer cost

lizzk: But trying to find how many people get lung cancer a year from any one cause is difficult

alpha137: That is a good start. These estimates are hard, but health associations like Cancer and Lung have done this because no one else was.

lizzk: Yes, What are their estimates?

alpha137: I have a book, quite old now, called "Statistical Compendium on Adult Lung Diseases" put out by the American Lung Association.

lizzk: ok

alpha137: The Lung Assocation needed to do this because to argue with industry and government it was necessary to show costs. Economists seem to take the easy road to cost determination-the costs of things.

lizzk: ok

lizzk: so what were some of the costs?

alpha137: I have not found the cost yet, but death rates for all kinds of things. Putting a price on a life will yield a cost!

lizzk: Yes, it is so terrible to read the numbers, they are often so astronomical

lizzk: It is a little hard (impossible rather), I would imagine, to put a price on life,

alpha137: Besides death there are simple things like days of lost work due to illness. This is a cost too and since there are large numbers of people these costs are big as well.

lizzk: yes,

lizzk: It gets up into the billions of dollars,

alpha137: I still have not found financial numbers, but as I remember the cost of air pollution estimate by the American Lung Association a number of years ago was from 3 - 10 billion. A large range because these are difficult estimates.

alpha137: The cost of flyash clean up is a reflection of the health cost of doing nothing with it.

lizzk: That is still a huge amount of money, I think that would be a powerful convincer in the public eye, it is the public money that is going to pay for all this(in the end)

lizzk: Yes, it would definitely be less expensive in the end to clean up after ourselves

alpha137: Right, and these estimates and arguements by the health associations in this country did have an effect on congress. The Clean Air Act is one such positive step.

lizzk: That is good

alpha137: Anyway, I thought that this little interlude on flyash and coal burning was useful and something I did not know about.

lizzk: Yes, me too

alpha137: Now, how about Lake Onondaga?

alpha137: This was a very interesting chapter.

alpha137: History and all.

lizzk: Yes,

lizzk: I thought so too

alpha137: What lessons do you bring away from this Onondaga story?

lizzk: I would say that the end is how important it is not to pollute, to keep the earth clean or else there will be bad repercussions in the future

lizzk: Also, the big lesson, that everything is interconnected, you can't change just one thing

alpha137: This Onondaga story is a classic case of the Tragedy of the Commons.

lizzk: yes

alpha137: I think that the only way to make an even comercial playing field and to protect health and environment is to have environmental regulation and laws enforced by government.

alpha137: There is an important role for government as an unbiased arbiter. If not unbiased then it is corupt.

lizzk: Yes, definitely,

alpha137: In the part on the Lake O story there is a description of the Solvey provess.

lizzk: Both sides need to have an equal say (of course, I think that the environmental side should win, but at least the other side should have a chance)

lizzk: YEs, the Solvey process.

alpha137: While I personally do not care much for the actual Solvey process the chemical and physical lessons are very good.

lizzk: yews

lizzk: yes

alpha137: Not only are there a number of chemical steps that are required to get the desired product, but there are economic efficiencies at work as well.

lizzk: yes

alpha137: Since thermodynamics (the Gibbs Free Energy is negative) for the overall reaction CaCO_3 + 2NaCl -> Na_2CO_3 + CaCL_2 says it is a go why all the steps?

lizzk: maybe to speed the reaction, all of the intermediaries are retained, so perhaps they are just catylists

lizzk: Or maybe it just makes it easier. Just because you put some nitrogen and some oxygen in a box doesn't mean that they will combine, there have to be certain conditions, like heat

lizzk: So maybe it is the same type of thing

alpha137: Recall the name of the barrier to a reaction (as the nitrogen + oxygen one)?

alpha137: XX energy?

lizzk: like gibbs free energy?

alpha137: No, the Gibbs Free Energy deals with the overall process-from reactants to products-but does not consider details of the reaction.

alpha137: Activation energy is what I was refering to. The Activation energy is the energy relative to the two reacting molecules needed to get them to react.

lizzk: oh, yes, now i remember. Sorry, but the other steps then, do act as catalysts to speed the reaction, lower the Activation Energy

alpha137: If molecular nitrogen and molecular oxygen collided with sufficient energy to overcome the activation energy they would produce NO. If the two molecules hit end on that would require a larger energy than if they hit side by side.

alpha137: This is a molecular view that does not have anything to do with thermodynamics (the Gibbs Free Energy).

lizzk: ok

alpha137: Right, it must be that the intermediate steps have lower activation energies.

lizzk: I didn't think that GFE was right, but it was a triy

lizzk: triy = try

lizzk: ok

alpha137: For some reason the book suggests that we mix CaCO_3, NaCl and water, but I would leave out the water and just heat the calcium carbonate and salt and see what happens.

lizzk: ok

alpha137: I would get that temperature so high that these two compounds would fuse together. Then I would heat it some more.

lizzk: my guess is that they will not combine

alpha137: Thermo says they will.

lizzk: Ok, they why didn't people do that, wouldn't that have been easier?

alpha137: No, because of the activation energy advantage of going the other route.

lizzk: or was it too espensive to make that option feaseable?

lizzk: ok

alpha137: Yes, I bet it was too energy expensive.

lizzk: i see

alpha137: Think of the CaCO_3 + NaCl system on a kind of chemical topographic free energy map.

lizzk: they are on either side of a mountain

alpha137: I guess we should put in the CO_2 and the NH_3 as well.

alpha137: Will the products, Na_2CO_3 + CaCl_2, are on the other side of the mountain.

alpha137: Will = Well,

lizzk: ok

lizzk: and the intermediate steps allow them to go around the mountain, through the foothills

alpha137: The carbon dioxide and the ammonia make the topographic energy map more complicated, but the idea is the same.

lizzk: ok

alpha137: Exactly right. The CO_2, NH_3 allow a path through the foothills.

lizzk: ok

alpha137: It then becomes a matter of deciding which path is cheaper.

lizzk: The straight path or the round about, i guess the foothills won,

alpha137: Empirically, it was found that the foothills won. But left out of the energy and economic calculation were environmental and health costs.

lizzk: yes, and they cancel out the advantages of the foothills path

lizzk: But they didn;t even know the environmental and health costs back then, did they?

alpha137: No, and it took fantastic disasters like Onondaga and a number of others to get peoples attention.

lizzk: But we could be making the same type of mistakes and not realize it for another hundred years or so, that would be a pity

alpha137: By the way, I took a look at the calculus based physics text. Probably not for you, but perhaps a good one to have around. Looks like it teaches some calculus using physics.

alpha137: Right, we need to continue to do research and study on environmental issues of all kinds.

lizzk: Ok, and thanks for the non-calculus physics text too. I got a message from a physics prof with the name of another one,

alpha137: We need to make it as quantitative as we can, but need to act when sufficient knowledge is obtained.

lizzk: yes

lizzk: but shouldn't all of these analyses be done BEFORE the problem, before the techology is implemented, if possible,

alpha137: Yes.

lizzk: for ex. CFC's they were a new invention, but then, how were they supposed to know what they would do with the Ozone layer

alpha137: Right.

lizzk: so it is really difficult

alpha137: In the case of NO in the stratosphere the way its potential impact was thought about was simply due to a chemist asking the question "what happens if NO is in the stratosphere?"

lizzk: but did that stop it from being used, or produced etc.

alpha137: This was prior to the idea that supersonic transports were to fly up there and inject tons of NO into the stratosphere.

lizzk: But at least he or she had that thought

lizzk: So that is why the concorde is the only one

lizzk: That is goo

lizzk: d

alpha137: The chemist was a former prof of mine at Stanford, Hal Johnston, now at Berkeley.

lizzk: I see

alpha137: He could see that NO would interact with ozone.

alpha137: This was before people were thinking about CFC's.

lizzk: that is good

alpha137: So, prior to anything happening, he had these thoughts.

lizzk: and now, there is lots of information out there about NO and the dangers of the nitrous oxides. Maybe the majority of Americans havent heard of its danger, but some has, and that number is hopefully growing

alpha137: He wrote down a series of chemical reactions which were the path of NO reacting with stuff in the stratosphere.

lizzk: ok

alpha137: He realized that whether or not NO was an important reactant in the ozone process depended on the speed of some of these reactions.

lizzk: i see

alpha137: He set about looking up these reactions speeds.

alpha137: He found a particularly important on and wondered where the number came from.

lizzk: ok

lizzk: where did it come from?

alpha137: He went to the papers and traced back author to author to the first author who used that number.

alpha137: Guess what.

lizzk: what

alpha137: It was a guess!

lizzk: oh no!

lizzk: so then did he go to figure it out himself?

alpha137: So Hal Johnston, being an expert on oxided of nitrogen, began the process of getting a real number.

lizzk: what did he find

alpha137: Yes, he did figure it out and found that it was not good for ozone.

alpha137: NO in the stratosphere is an ozone killer and therefore SST's in the stratophere, in sufficient numbers, are not good.

lizzk: Ok, thats too bad,

lizzk: I see

alpha137: This had economic consequences. And national pride on the part of the British and the French.

lizzk: yea

lizzk: yes, but it worked, we don't have SST's now

alpha137: Also, the american airframe industry did not like this idea and the Nixon presidency became interested.

lizzk: ok

alpha137: Pardon me for a couple of minutes, I have to go pick up some exam books from some grad students.

lizzk: I can imagine me

lizzk: nevermind, thats ok, IN fact, I should probably go now

lizzk: I have to be somewhere soon

lizzk: I don't know what is wrong with me today, I am not speaking english very well at all, I must be more tired than I though.

lizzk: thought

alpha137: Ok, I am back. How about one last time next Thursday?

lizzk: ok, that is fine with me, Thank you,

lizzk: Bye

*** Signoff: lizzk (Leaving)