Coal as a Resource

I don't think you can eliminate coal that easily...

http://www.eia.gov/forecasts/ieo/coal.cfm

..."The largest single use of coal in the steel industry is as a fuel for the blast furnace, either for the production of metallurgical coke or for injection with the hot blast. Other less commonly thought of uses of coal is for making steam and electricity, as sources of carbon addition in steel making processes, and in direct smelting of iron processes. Furthermore, electricity purchased from outside sources is largely generated from pulverized coal combustion and therefore has an indirect influence on steel making operations."...

http://www.steel.org/making-steel/how-its-made/processes/processes-info/coal-utilization-in-the-steel-industry.aspx

If coal production was abruptly curtailed then I believe all sorts of nasty things like rolling electricity blackouts, pockets of economic catastrophe and the end of most steel production in this country. (Wait, didn't my last prediction already happen?) Good things will also happen like less mercury in the environment and a reduction in acid rain in the North East but every improvement has its complications, don't they.

If coal production is gradually curtailed to almost nothing then the good effects will be delayed but the harsh economic impacts from an abrupt change will likely disappear.

Like today's buggy whip manufacturers a very few mines may be able to sustain production in a niche market. But only if only coal supplies an elite quality to some industries (steel(?)) in their production.

For the sake of argument, let's focus on steelmaking. To make steel, you need coke (made from coal) for smelting iron ore, and a source of very high heat. Can iron be smelted without coke? Does the heat have to come from coal, directly or indirectly? I'm not up on the steelmaking process despite spending nine years in Pittsburgh (when Big Steel was in its death throes -- the air was clean enough to breathe).

Where I'm going with this is that if we use coal only for steelmaking and stop using coal-fired power plants to generate electricity, some huge amount of the byproducts of burning coal will no longer pour into the atmosphere. If there's a way to reduce the amount used in steelmaking, so much the better.

The carbon in the coal is not only for a heat source but combines with the iron to form steel.

https://en.wikipedia.org/wiki/Carbon_steel

Yes, that is a key point. Some carbon has to be added, or it's just pig iron.

Carbon does not necessarily have to source from coal, but that is the traditional way.

As a former fuel technologist and researcher into coke-making (for iron/steel production) I can relate that the production of steel requires that carbon [present in the hot metal from the blast furnace] is removed via contact with oxygen(BOF) or air (Bessemer) both of which release CO and CO2]; the carbon in the Hot Metal is directly from the solution of carbon in the coke (ie: coal). Also note here, not all coals are "coke-making" coals. It seems that there are a lot of big political issues here (especially related to the Global Warming controversy) and political or environmental faction wants to address them.

Anyway, use of Electric Arc Furnace melting of re-use scrap steels can produce fresh steel without coals, but not much new steel; that new steel has to come from countries willing to use primarily the Blast Furnace/BOF route (namely China and India). Use of the Electric Arc Furnace route requires electric power (duh) which can be made with coal burning, oil burning, solar, wind or geothermal sources. While we have large coal reserves in the USA, we need to ask where it is currently being shipped.

Yes, carbon is the reducing agent in a blast furnace, also CO. Too much CO is not good, however, since traces of iron carbonyl might form, a deadly gas at high temperatures, so I believe, if starvation of oxygen takes place. At room temperature this is a yellow liquid that is volatile.

It is used for making transformer iron, injection iron for molding, etc. through decomposition by burning to carbonyl iron (pure iron of microscopic particle size).

The synthesis route of this seems to require an aggressive approach with very high pressure CO, so probably not much would actually be present in a blast furnace and that should burn away. Probably a completely moot issue.

I think the carbon needs to be pure enough and low sulfur enough to not affect the grade of the steel produced. During crystallization of steels, the much of the carbon is interstitial carbon, but it is undesirable to have larger carbon voids as that would ruin tensile properties, and leave the manufacturer with a brittle steel that is worthless than pig iron.

Thanks, Lyn. Both those links are interesting and right on point.

In addition to shutting down a lot of steel making if zero coal application is allowed, it would shut down the majority of magnesium production from the oxide (Chinese method), nearly all foreign silicon production, and have a substantial impact on the cost of basic chemical commodities, as well as drive up the cost of aluminum primary recovery. The cost of hydrogen gas in some areas would go up.

Primary use of steel would vanish. Steel recycling would be the only source of steel, and this eventually reaches diminishing returns.

Pretty grim picture overall. Not a good way to expand a global economy.

Thanks for bringing up the natural gas fired iron ore reduction method, that one makes a lot of sense! If one looks at flame temperatures achievable, I think the comparison is favorable, and the flame can be made into a reducing flame, which is the requirement to wrestle the oxygen away from iron.

I cannot see this trick working with magnesium production, or silicon production. Not to mention the Chinese simply dump a lot of cheap metals to the world market won the old way with carbon reduction method.

Never heard of iron lung machine, huh. (just joking, don't blow a fuse).

If the powers of this world were serious about any of the HICC (formerly called global warming), pollution by mercury, particulates, etc,etc, then all would re-engineering their coal burning power plants to the point that there is no emission, period. The obvious reason is cost versus competitiveness in a real world market global economy.

Some countries will always try to win the game by placing their rather heavy thumbs on the scales of equality, especially the ones that do not have a word for equality in their lexicon.

It takes a hell of a lot of technology to burn coal in a boiler and have no or virtually no emissions at the stack, and some of this technology is still emerging. It simply does not arrive on a Gigawatt level site without millions of dollars being spent.

As far as cleaning up steel production, good luck with that. Just know that steel producers in most countries want the best, cleanest coal they can get for coking operations, since it is more efficient for them to do so, the carbon introduced to the steel production (blast furnace) is purer, and helps control the content of the steel, etc. Good luck putting a string around the stack of one of these plants, or cleaning up the fugitive emissions either. I think they already have done about all that is practical to do.

The real problem, as I have already stated is countries that insist on not only steel production the old way, but also magnesium, silicon, and a host of other metals.

Thanks for the info. Funny; I live in South Mississippi and I don't smell any coal burning.

That's because the nearby nukes have seared everyone's nasal passages. Not.

They have coal in south Mississippi? I thought you guys only had mud over there.

Then spare a thought for CR4 readers who live near Xi'an, China.

Some of my posts in the past have advocated gradually replacing coal generated electricity with fast nuclear generation. This is still true, and it is becoming more important as global warming proceeds. Wind and solar cannot have enough capacity to produce all the energy we need. The "huge" dangers of nuclear that some advocate are mostly hype and untruths, because nuclear has a very good safety record.

From previous posts, some coal will be required, so it can't be eliminated completely. However, it can replace coal-fired electricity generating plants.

I will tentatively agree with you about nuclear, but only if we get off the old designs, even the Navy's light water reactors could be utilized as a size reference for cookie cutter nuke plants.

The new molten salt designs run on spent nuclear fuel, of which there is at least a 200 year supply already. The designs are incredible products of ingenuity, clear-minded consideration of safety margins, and emergency scramble of the reactor if power is lost in the plant. They need to not only be looked at, we need jobs in the industry, and building about the first 100 of these requires a workforce of immense size.

It also requires quality work, not slap and dab kind of work.

I'm not personally qualified to comment one way or the other on the proposal made in this video but as a layman it sounds like a pretty strong argument for Thorium reactors so I'm wondering can anyone here refute what he's saying, and if not, why isn't it getting more attention and backing?

In the video's accompanying text it says that Thorium research was being funded in the US 50 years ago but then the rug was pulled because the by-products can't be weaponized.

Could that point of view be reassessed now in view of interim findings and incidents?

https://www.youtube.com/watch?v=uK367T7h6ZY

Wrenchtwirler: I'm not a nuclear engineer, but I have learned a fair amount about the Integral Fast Reactor (Metallic fuel, sodium cooled) Practically all he says about Th as a fast reactor fuel is true; however, Th is only one of the elements available for fuel. Fast reactors will also use U238 (depleted uranium), Th, the actinides in the thermal reactor waste, the U or PU from decommissioned nuclear weapons, etc. All fast reactors are much more efficient than thermal reactors. The video shows the small amount of U-235 in natural U (.71%), which means all the rest is available for fast reactor fuel.

Why isn't it getting more attention? IMHO because of the public's unreasonable fear of anything using the words nuclear or radiation. The current Linear, No Threshold (LNT) theory is obsolete and has been disproved. In fact some small amount of radiation is apparently good for us.

Fast reactor research was cut off in 1994 for political reasons when they were very close to a solution.

Yes, we need to reassess, but do not limit to just Th.

Thanks for that.

I guess you could put me in the category of a public with unreasonable fears but with myself it's more a fear of politicians and the corruption they are exposed to, which makes me doubt that logic will override greed when it comes to deciding what is best for our future.

Spent nuclear fuel is not really spent, it is just no longer any good for light water cooled reactor. It will work great in molten salt reactor where fuel is dissolved in the molten salt, and these reactors are tres bien safe.

renaissance of nuclear power has been stymied by the Fukushima incident

Mostly because of media hype building on the people's fear of anything associated with the word "nuclear." There were several deaths and many health problems due to the stress of the evacuation, but very few (maybe none) among the workers. Fukushima was not a nuclear problem until the tsunami knocked out the backup electrical power supply.

So, put the power plants inland.

Palo Verde Nuclear Generating Station - Wikipedia, the free ...

"The Palo Verde Nuclear Power Plant is located in the Arizona desert, and is the only large nuclear power plant in the world that is not located near a large body of water."

It's 55 miles west of our house and I never give it a thought because I feel it is safe.

So is Palo Verde air cooled? Or is it sucking up vast amounts of water for cooling towers from the Colorado River?

Neither.

It evaporates 20 billion gallons a year of treated sewage purchased from nearby cities for cooling.

using treated effluent is not new, and Excel does this at any plant they have where they can source it. I think they actually prefer it over other sources, because it does a "solid" for the environment, and the source is usually cheaper.

What happens to the sludge left over after the evaporation?

I don't know what the solids content is, but most of the solids are removed at the treatment facility prior to pumping to the holding pond on site.

Note that I stated this is treated final effluent from the POTW, all the floaters and sinkers, and ones in between have been removed through the magic of biological science, filtration, etc. The etc. is the exciting part of the process, since it takes an electrical discharge in a mixture of gases including oxygen to make ozone, which a really good final step.

No one in their right mind or in their wildest dreams would run a cooling tower on raw sewage unless they were hosting a "Return to the Hanoi Hilton" event.

As to the dissolved solids remaining in the concentrated blow-down from the cooling towers, some of these plants have impoundment lagoons that actually water livestock with the water. Others reduce this down through water recovery processes to the point of recovering salt crystals on plate and frame filters, and dropping these salt solids down into a roll-off dumpster, but mineral blocks could be made. Also, it is possible to make road salt, or brine from the blow-down, depends on economics, and will to have zero liquid discharge.

lack of a long-term solution for highly radioactive spent fuel cells

But we do already have a solution to the highly radioactive spent fuel. This solution is the fast neutron nuclear reactor, which uses high speed neutrons instead of thermal neutrons. The transuranic actinides are the elements that are highly radioactive with long half-lives. These actinides are fissioned in the fast reactor to make even more electricity for the world to use. As a result, they no longer exist! The actual waste is about 100 times less in both volume and radioactivity, and needs to be isolated only a few hundred years instead of hundreds of thousands.

The funding for developing this resource was cut off for political reasons in 1994.

Can coal burning power plants be converted to gas burning? It would seem to be an economical way to switch to a cleaner fuel.

Since most (all?) coal fired electric power plants boil water to spin a steam turbine they certainly can be refitted to use gas fuel for that heat. The old coal steam turbine facility might be the second stage in an efficient cogeneration process where the burning gas happens in a gas turbine that spins a dynamo with the exhaust heat boiling water for the old steam turbine.

The question of cost always comes into play when retrofitting any machine for another purpose.

Likewise, coal plants can be refitted to use fast nuclear as the heat source. For fast nuclear, liquid sodium, liquid lead, etc are the primary coolant loop. This hot liquid then boils the water in a secondary loop if I understand correctly. (I'm not sure how molten salt is arranged.) Using fast nuclear for heat instead of coal, lets the existing infrastructure be used (generator, transformers, transmission lines, etc,)

They do have modular nuclear reactors now that conceivably can be dropped into the ground onsite, but it would take a lot of them per former coal site. These are rated at about 50-150 MW range, but the old coal plants can be as large as 1-2 GW.

I would like to see the large enough gas turbine with large enough waste heat to even spin up the formerly coaled fired steam turbine to sync idle.

Industrial Boilers: Fuel Switching Methods, Costs, and Environmental ...

The entire burner and blower structure has to be re-worked, $$$$.

The good thing is that the coal will wait patiently in the ground until it is needed again. It can't leak out or drain away.

Not that I have a lot to add, just some perspective.

I have worked at coal fired plants for many years, as well as plants that use tertiary effluent from city sewage treatment facilities. As an engineer in training, one of my first assignments was to join a couple of plant maintenance men in the basin of a forced draft cooling tower which had been using effluent since the early sixties. The assignment that day was to clean out the sludge.

First off, that stuff does NOT flow downhill, but just sits there until you hit it with the a blast from the fire hose and keep pushing it until it hits the drain channel! It was a green-brown gelatinous mass about 6 feet deep covering approximately the same surface area as one and half football fields. I immediately got an appreciation for water treatment assignment.

And then, after we had concentrated the salts by evaporation, we used the blowdown from the cooling towers to raise crops, or feed for livestock in the area. Fascinating science in all of that, and good use of an important resource in a semi-arid climate.

And secondly, I worked for many years both with the equipment in the coal fueled plants, and in environmental compliance for those facilities.

I think the best comment from one of my cohorts at corporate was his proposal for our production department slogan, "We Burn Coal So You Don't Have To!" Of course, that was back in the early 80's when we were all convinced that natural gas was coming to the end of availability. Now gas seems to have recovered nicely and the burning of coal an act of macro aggression!

I was intimately involved with all the numbers and results from testing the coal and gases from the plant. I also am well acquainted with the assumptions that must be plugged into any complex atmospheric model, and the enormous degree of different results that result from small "tweaks" in the variable affects. I am also skeptical of the data mining that is done in support of either side of "scientific" support of those results. For that reason, I question the value of widely acclaimed but rarely independently tested "consensus" as a valid scientific method.

But the one certainty I do have is that wholesale withdrawal of what has been the major source of power for our nation will NOT be an easy change, and WILL leave our industrial base in grave danger. The United States electrical grid has little excess capacity or robustness as is, and, particularly during time of heavy demand, would be subject to massive failure with a relatively small loss of capacity as it now is. Renewables are interesting, but do not provide the reliability or flexibility of easily dispatched fuel-driven generators.

That experience in the cooling tower basin alone should tell an engineer that not enough was being done upstream of the tower. Although, I myself find even small amounts of sludge from using city water (shameful practice, but the City will not make treated effluent available to us). That sludge also arises from wind-blown dust in the air, mostly. Have though about use of manifolded angled water-jets in the basin, to progressively "sweep" the sediment over to one side where it should be picked up and pumped through a filter, the water being returned to service basin. Usually the cost of such schemes is not justified, however, due to other engineering controls, the level of the "problem", and the water source and suitability for cooling service.

I have to admit that the sludge was not at all mostly poop, but you have to recognize that treated effluent is a nutrient rich source of water. Combine that with hyper oxygenation from being splashed over a tower with fast air flow and sunlight, as well as frequent and profuse "windborne indigenous matter" and give it 24 months to create the soup.... Yeah, it is mostly organic and growing! Of course, there were rare events when the city treatment plant got overwhelmed and sent some untreated waste, and even when the treatment system was working, a lot of "personal" items which frequently get flushed down the toilet come through relatively unscathed (by the truckload). We had our own final flocculation system that caught most of that.

It was a fast lesson in what reuse really implies.

Yes. Hopefully, the next ones to do that do not decide to re-invent the wheel.