I mentioned in my previous post that I had been puzzling over the statement that moisture in coal caused (or increased the likelihood of) spontaneous combustion. Well, I finally got around to doing a little searching on "spontaneous combustion coal", and this one discusses the effect of moisture in a little more detail than some of the others:
https://practicalmaintenance.net/wp-content/uploads/Spontaneous-Combustion-of-Coal.pdf
Discussion of moisture begins on page 8. I still don't claim to fully understand it--it still seems counter-intuitive to me that water causes fire.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
Paul of CovingtonI still don't claim to fully understand it--it still seems counter-intuitive to me that water causes fire.
It takes a lot of water to extinguish a fully involved barn fire.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Yes, Larry, the proper care for hay was impressed upon me when I attended a 4-H camp the summer after I was in the sixth grade. There was quite a presentation of the necessity of making sure that the hay was dry, even to the point of having exhaust fans in the loft.
Johnny
Paul of Covington I mentioned in my previous post that I had been puzzling over the statement that moisture in coal caused (or increased the likelihood of) spontaneous combustion. Well, I finally got around to doing a little searching on "spontaneous combustion coal", and this one discusses the effect of moisture in a little more detail than some of the others: https://practicalmaintenance.net/wp-content/uploads/Spontaneous-Combustion-of-Coal.pdf Discussion of moisture begins on page 8. I still don't claim to fully understand it--it still seems counter-intuitive to me that water causes fire.
Spontanious combustion of coal is caused by oxidation of the coal when that raises the temperature above the ignition point. Oxidation is proportional to surface area. Wetting and drying causes the coal to break apart, and enhances surface area. Ther is also heat of wetting which raises temperature. The article recommends that coal pile hot spots be removed and spread out to disapate the heat of oxidation. They say wetting the pile is poor management, and will eventually create conditions for faster oxidation.
MidlandMike The article recommends that coal pile hot spots be removed and spread out to disapate the heat of oxidation. They say wetting the pile is poor management, and will eventually create conditions for faster oxidation.
The same method is used for hay, although getting to the middle of the hay in a 100' x 60' hay mow can be a challenge. There are thermometers made to check that - basically a long pole with a pointed end and a thermometer at said end.
Responded once on mutual aid with our tanker to a reported barn fire. Usually you can see them for some distance - there was no "header."
Despite the best efforts of firefighters, the barn ended up on the ground - they just couldn't get the hay out fast enough.
MidlandMike Ther is also heat of wetting which raises temperature. The article recommends that coal pile hot spots be removed and spread out to disapate the heat of oxidation. They say wetting the pile is poor management, and will eventually create conditions for faster oxidation.
That's part of the puzzlement. Earlier in this thread Murphy mentioned seeing piles of coal being wet down, and I think I remember mention in a thread some time ago of coal in hoppers being wet down.
Paul of Covington That's part of the puzzlement.
I suspect that it's because it's counterintuitive, as has been mentioned.
One reason for that is likely the thought that coal is just rocks that burn, when it's much more than that.
With the advent of the huge round and square hay bales, many are stored outside now. If they catch fire (for any reason), the pile will be torn down, oftimes finding hot spots that had yet to ignite.
Coal is organic so it can ferment, and that process can create heat. Back in the day of rectangular hay bales that were put up in a hay loft in a barn, many a barn was lost to the hay bales catching fire from being put up wet. Even today with round bales stored outdoors farmers will cut the hay and let it lay to dry before it is baled.
The "dampness causing fermenting which causes heat which eventually causes fire" does make sense.
One of the postulated causes of the massive fire that destroyed the Marcal Paper Products plant in Elmwood Park NJ during the winter was spontanious combustion caused by wet and rotting paper products, although it does sound counter-intuative.
I have no idea at this point just what the cause of the fire was. The northern New Jersey news cycle's moved on and there's no mention of the disaster anymore.
kgbw49 Coal is organic so it can ferment, and that process can create heat. Back in the day of rectangular hay bales that were put up in a hay loft in a barn, many a barn was lost to the hay bales catching fire from being put up wet. Even today with round bales stored outdoors farmers will cut the hay and let it lay to dry before it is baled.
Coal (mostly carbon) may be subject to biological degradation, but nothing like the rate of fermentation, which hapens with plant sugars (carbohydrates). I find lumps of coal in my yard from the time when the house had a coal furnace, so the coal has been sitting out in the environment at least 50 years, and probably much longer, but shows little sign of damage.
Paul of Covington MidlandMike Ther is also heat of wetting which raises temperature. The article recommends that coal pile hot spots be removed and spread out to disapate the heat of oxidation. They say wetting the pile is poor management, and will eventually create conditions for faster oxidation. That's part of the puzzlement. Earlier in this thread Murphy mentioned seeing piles of coal being wet down, and I think I remember mention in a thread some time ago of coal in hoppers being wet down.
That may have been a sealant being applied to keep dust down.
The municpal power plant at Fremont, NE employes end loaders to regularly move around the coal in piles. It's not unusual during holidays when staffing is less to see little hot spots develope because they're not moving the coal around.
I've heard of a car having to be unloaded because the coal started burning due to spontaneous combustion.
Jeff
Fermentation to produce alcohol requires plant sugars. However, fermentation is the biological breakdown of a substance by bacteria, yeasts or other microorganisms that results in effervescence and heat. If you have dry coal piles up above the fermenting coal, trapping the heat, you will get smoldering and then a fire. A lump of coal in your back yard does not ave a pile of coal sitting on top of it holding in the heat. Coal pile fires start from the chemical reaction of fermentation causing heat that builds up and eventually starts rapid oxidation via combustion, also known as “fire”.
I doubt fermentation is the cause of too many coal fires, where the problems are likely related to orimary oxidation and presence of sulfur compounds as promoters. Aggregation of fines either is a problem, as the high exposed surface area and relatively good insulation value allows faster thermal buildup. There is a famous case from the early '90s where a lump of wet fines clumped on a backhoe tire spontaneously ignited as it dried out.
I'm glad everyone here seems to know that spontaneous combustion of paint rags is a completely different thing: runaway polymerization promoted by 'driers' that are actually crosslinkers.
If you watch trains at all, whether thats via a web cam, or you're out there, very quickly you will see that coal trains are still alive and well.
As an example, on one rail cam in Kearney NE, I watched for three hours. Six trains were coal, three Intermodal, and four Manifest.
Friday, on Stampede Pass, I saw three coal trains. I was there for an hour.
"as long as there are users of Coal. it will be hauled by trains"... No words could be further from the truth.... and it seems this countries power grid still cannot fully function without coal, because the rails are still hauling it, even with exports.
My two cents...
CNIowa"as long as there are users of Coal. it will be hauled by trains"... No words could be further from the truth.... and it seems this countries power grid still cannot fully function without coal, because the rails are still hauling it, even with exports.
In 2018 coal was used to generate 24.8 percent or 93,249,395 MWh of Texas' electric energy. Fifteen years ago, it was more like 45 percent.
While still a significant factor for Texas's electric utilities, coal as a boiler fuel is on an irreversible decline.
Natural gas is the go-to fuel for electric generation in Texas. In 2017 it was used to generate 38.8 percent of the state's electric energy. In 2018 it was 44.4 percent. Wind generated 18.6 percent, up from 17.4 percent in 2017.
The nation's electric utilities burned 10,384,000 tons of coal in 2018. If all the coal was moved to the coal burning power plants by rail in 120-ton cars, it would have required 86,533 cars to get it there. That would make for a large number of trains to observe.
Of course, not all the coal goes by rail. At least in Texas, some of the coal is lignite, which is mined near the power plants, and is usually taken to the plants by truck, conveyer belts, or company rail.
Gas is cleaner and much easier to handle than coal. No ash, no exhaust treatment (ash precipitators and scrubbers) and no heavy equipment to haul it around. And now it is cheaper than coal, thanks to the fracking boom.
Under the current circumstances, what reasonable profit-oriented power company wouldn't want to make the switch?
Greetings from Alberta
-an Articulate Malcontent
kgbw49 Fermentation to produce alcohol requires plant sugars. However, fermentation is the biological breakdown of a substance by bacteria, yeasts or other microorganisms that results in effervescence and heat. If you have dry coal piles up above the fermenting coal, trapping the heat, you will get smoldering and then a fire. A lump of coal in your back yard does not ave a pile of coal sitting on top of it holding in the heat. Coal pile fires start from the chemical reaction of fermentation causing heat that builds up and eventually starts rapid oxidation via combustion, also known as “fire”.
While the lumps of coal in my back yard don't have a coal pile above them, I would think after 50+ years of "fermentation" they would have disintegrated by now. In the article referenced by the OP, the author (a coal expert) shows that the coal pile fires are started by physical oxidation, and are near the surface where oxygen is available. Properly compacted piles, that deny oxygen pathways, keep fires from starting in the interior. He also mentions heat of wetting and pyrite breakdown. Volatiles would also contribute to a fire. He mentions noting about biologic activity as a contributor. In your bottom of the pile fermentation scenario, any oxygen would quickly get used up and limit further oxidization.
CP is hauling a few crude oil trains over the former Milwaukee Road twin cities main. I remember the old Coal Contract that the Milwaukee used to share with BN back in the old days for a large Coal Powered Plant...........was it called Columbia II???? Mile long Powder River Basin Coal Train. Not sure but I no longer see it under CP Rail. That was back in the late 1970's. Sometimes powered by Milwaukee units, sometimes BN units. Always had a nice Silver Burlington Route (rare) or Green BN Caboose.
Yes, gas is much cleaner than coal. When I was in college, there were four boiler rooms on the campus, and the coal bins were filled in the summer. To fill three of them, the driver of the delivery truck backed up to the opening in the wall, and shoveled 7 tons of coal into the bin as he worked in the fresh air--and two boys inside threw the coal to the sides. Yes, I was one of the two boys several times. The fourth boiler room was down hill from where the truck came in, and the driver simply dumped 12 tons of coal through a hatch in the roof.
Never were the coal bins emptied, and the coal in the far corners sat there over the years--and was never oxidized.
And then there are those who want to get rid of natural gas, as well...
They're going to have a tough time getting whale oil for their lanterns.
tree68They're going to have a tough time getting whale oil for their lanterns.
Don't be silly; whales are protected species now, even if Japan tries to 'do their worst'.
The correct answer is lots of LEDs from China, powered by cheap batteries from China, charged by solar panels ... and for lighting, even cheap solar panels get the job done well without limited lifetime.
Space conditioning is the big thing that has to be accomplished. There is just so much that can be done with passive solar and 'green' architectural conventions...
The correct answer is lots of LEDs from China, powered by cheap batteries from China, charged by solar panels ... and for lighting, even cheap solar panels get the job done well without limited lifetime. [/sarc]
I think we should go back and look at the original question that was posed. Nobody I know of ... no one sane, that is ... made a particular effort to retain the Timken stoker and tin 'ashcan' era of home heating much past the 1950s. There is now no use of coal for domestic heating outside an enthusiast's niche market, and the colossal infrastructure to provide it (including no few 'anthracite roads') is withered up and gone.
The 'electricity fairy' is little different: provision involves the lowest cost, and EPRI members are extremely good at assessing what that is, right down to the capital cost to make changes. I can think of few plants using a Rankine cycle that are more efficient than a good Cyclone furnace ... but there are various pollution problems that are difficult to solve for that style of combustor, even if we relax constraints on cost-effectiveness. On the other hand, good GTCC offers comparable thermodynamic recovery per lb. of fuel, and piston engines (or other positive-displacement means) have better part-load efficiency where high turndown is expected in service.
The question remains whether the cost of natural gas for electrical power production remains adequately low as the fracking boom comes to a close -- and I expect this to be accelerated under any sort of 'green New Deal' arrangement as activist politicians begin to demand the 'proprietary' composition of the fluids and regulate their use -- and numerous other uses for the produced gas begin to compete with the electricity fairy and raise the opportunity cost. Doubt that this would spur a 'return' to clean coal with its mandatory reduction of both cycle efficiency and fuel economy per generated kW ... but stranger things have happened.
Yeah, leave Moby Dick alone!
Poor big guy, just swimming along minding his own business and then some psycho comes along and sticks a harpoon in him! No wonder he got PO'd and bit Captain Ahab's leg off! What would YOU do?
Save the whales!
Overmod, I'm glad you brought up the "electricity fairy." This is something that drives me nuts, as far as generation of electricity is concerned.
Let's see, coal is bad, oil is bad, natural gas (from fracking) is bad, windmills are bad because they kill birds, solar panels are bad because they're eyesores. And don't even bring up nuclear power!
Where do people think the "juice" is going to come from? There's no "electricity fairy" and Saint Thomas Edison can't send it down from Heaven. Sheesh!
Flintlock76 Yeah, leave Moby Dick alone! Poor big guy, just swimming along minding his own business and then some psycho comes along and sticks a harpoon in him! No wonder he got PO'd and bit Captain Ahab's leg off! What would YOU do? Save the whales! Overmod, I'm glad you brought up the "electricity fairy." This is something that drives me nuts, as far as generation of electricity is concerned. Let's see, coal is bad, oil is bad, natural gas (from fracking) is bad, windmills are bad because they kill birds, solar panels are bad because they're eyesores. And don't even bring up nuclear power! Where do people think the "juice" is going to come from? There's no "electricity fairy" and Saint Thomas Edison can't send it down from Heaven. Sheesh!
Well, I was being facetious, but the "electricity fairy" really hits the nail on the head. Although you forgot hydro power, and those poor fish...
The whale oil comment was really pointed at those who think their food magically comes from the grocery store.
Don't worry Tree, I know you were joking about whale oil!
Oh yeah, I forgot dams are bad too!
Flintlock76 Where do people think the "juice" is going to come from? There's no "electricity fairy" and Saint Thomas Edison can't send it down from Heaven. Sheesh!
Maybe one to two percent of the population has some idea of how electricity is generated, transmitted, and distributed. And this would be on a good day.
From the focus groups that we ran in conjunction with deregulation of the electric utility business in Texas, as well as Australia, we learned what most people want from their electric energy provider: When they flip the light switch, they want the lights to come on. If they don't come on, they want to know who to call. And they want an electric bill that does not wreck the family budget. That's it.
A significant percentage of the focus group participants believed that we were grabbing the energy out of the sky and charging people for it. I suppose they believed the harvest was really good during an electrical storm. I kid you not.
There are some unbelievably ignorant people in this country, although I suppose it is no worse than most other countries. So, maybe Saint Thomas Edison is not as far fetched in the minds of some people as one would suppose.
JPS1, your comment about "unbelievably ignorant people" is spot-on. It's the reason so many are easily manipulated by others who want their money or their votes, or both.
Make you wonder just what the hell's going on in the schools nowadays.
I hate to sound like a grumpy old geezer, but "back in my day" we had at least some idea of where the electricity came from, where the water came from, and where the food in the supermarkets came from, to say nothing of a basic understanding of industry. We knew it didn't come from nowhere, and the standard of living we enjoyed took a lot of hard work on someone's part.
JPS1 A significant percentage of the focus group participants believed that we were grabbing the energy out of the sky and charging people for it. I suppose they believed the harvest was really good during an electrical storm. I kid you not.
Probably because all those touting solar and wind generated electricity claim it's practically free because there are no fuel costs.
I'm not worried about the greenies being able to curtail fracking and natural gas production. They won't have to. Once everything is dependent on the supply of gas for everything, the suppliers will curtail it on their own to drive up the price. I expect them to all of a sudden find religion and come to the conclusion that fracking is bad and has to be curtailed. So much for having a utility bill that doesn't wreck the family budget.
Some rather strange comments here. Solar isn't free because it takes equipment to turn it into electricity and distribute it, same as gas and coal. But the source of power itself, sunlight, is free, gas and coal are not. And solar power doesn't necessarily have to be distributed because the conversion to electric is a single step. Panels = electricity. I have solar on my roof, and a negative electric bill. Notice all the solar panels near control points on railroads, to power their signals. Some private company buildings have solar panels on their roofs. Forget "green" if you like. The fact is solar is often the cheapest way to go.
What is the cost of the panels to absorb the power from the sun? What is the life of the panels?
Our community is FREE to join. To participate you must either login or register for an account.