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Re: COAL Cogeneration

Posted: Wed. Nov. 07, 2018 12:24 pm
By: BigBarney
The best I've seen in co-generation is where a power plant is

the supplier of electric to a community and then all the waste

lower level heat is used in processes , like drying cereal ,and

finally used to heat something like a greenhouse or houses.

This way you use more of the energy contained in the fuel.

BigBarney

Re: COAL Cogeneration

Posted: Sun. Dec. 30, 2018 11:52 am
By: TheScrambler92
Have you ever heard of Peltier plates? They use temperature differentials to generate power (albeit, a miniscule amount). Methinks one could set up a metal sheet between your stove and a cold wall, loaded with peltier plates in parallel (or series, depending on the demand) and you could probably power a light bulb with it :lol:
A very interesting discussion nonetheless. Steam, although powerful, is too dangerous as stated before, and would require very careful monitoring, probably too much to make it worthwhile. Not to mention the mass quantities of water it would require to run a small turbine (and the noise!!!)

Re: COAL Cogeneration

Posted: Sun. Dec. 30, 2018 12:26 pm
By: jrv8984
Yeah, I've looked at them a little bit, very disappointing. Was thinking that if I could come up with a way to gasify or liquify the anthracite, I could fuel a lister engine to make electricity, and use the heat from the engine and from the gasification/liquification process to heat the house. Lots of interesting micro Chp systems, but none of them are capable of using anthracite, at least the ones that I have contacted. I haven't found anything useful on building a anthracite gasifier/liquifier.

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 3:09 am
By: AllanD
confedsailor wrote:
Tue. Oct. 30, 2018 2:34 pm
That was those high pressure jobs like on Cans and Fast Oilers. 1500 psi with few hundred in superheat on top.
That is because a steam turbine's efficiency is proportional to the boiler output pressure, the higher the pressure the more efficient they are.

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 9:17 am
By: confedsailor
AllanD wrote:
Mon. Feb. 11, 2019 3:09 am
That is because a steam turbine's efficiency is proportional to the boiler output pressure, the higher the pressure the more efficient they are.
Yup I know... spent 10 years in the "boiling water with hot rocks" business. Granted the rocks we used were Uranium...

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 2:35 pm
By: AllanD
confedsailor wrote:
Mon. Feb. 11, 2019 9:17 am
Yup I know... spent 10 years in the "boiling water with hot rocks" business. Granted the rocks we used were Uranium...
Fuel pellets welded inside of stainless steel pipes, I've always been somewhat amused by how much energy is eventually extracted from each of those wood pellet sized lumps of Uranium Oxide...

But it also bothers me that the guy who "invented" the light water reactor, also had a better idea for power generation and was eventually fired for pushing that other idea...

No not fusion, which I believe to be a pipe dream, but using the far more common Thorium as a fuel instead of Uranium, plus it would solve the "what do we do with the spent fuel rods" issue" by burning them up in thorium reactors.

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 2:54 pm
By: McGiever
AllanD wrote:
But it also bothers me that the guy who "invented" the light water reactor, also had a better idea for power generation and was eventually fired for pushing that other idea..
Surely this method didn't get ignored simply because it was 'better'...that makes no sense.

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 2:55 pm
By: McGiever
A fissile fuel must not be too easy to obtain, handle, or be stolen so then to be made into any nuclear weapon...kinda throws out anything too simple for nuclear electric generation...nuclear budgets for security add heavily to nuclear generation costs...where the other fuels, coal, gas and renewables have much, much smaller security budgets...

I'd venture a guess...without the steep security cost involved in nuclear generation that it could easily beat all other fuels on price to generate...

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 3:51 pm
By: AllanD
McGiever wrote:
Mon. Feb. 11, 2019 2:54 pm
Surely this method didn't get ignored simply because it was 'better'...that makes no sense.
It got ignored because the method could not also be used to make Plutonium for Bomb fuel, though an operating Thorium reactor is REALLY a reactor that runs on U-233 which itself is a fertile material that you could make a bomb from.

The really slick thing about a liquid salt reactor is that the Thorium Fluoride is a molten salt, while Uranium Fluoride is a gas, so unlike a light water Uranium reactor there are various ways for rapid safe shutdown. Draining the molten salt into subcritical ammounts releasing the uranium gas from the reactor vessel similarly.
One of the chief advantages is it operates at a far higher temperature, but not under LOW pressure. so the heat generated could be used to heat ...say Helium to extreme tempt and use it to drive gas turbines more efficiently than steam turbines.

The other thing is it can be operated more like a naval propulsion reactor and so the output could be varied rapidly unlike common power generation setups

Lastly Thorium is FAR more common than Uranium, thus cheaper
As I recall Uranium is about as common as gold, but only 0.35% of it is the U-235 they are really after.

Supposedly there is 800 MILLION tons of the stuff already dug up and sitting on a mountain side in Montana

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 4:19 pm
By: lsayre
Sounds about right, but I'm fairly certain that after undergoing gas centrifuging, uranium hexafluoride is subsequently returned to the state of being metallic uranium (albeit enriched via centrifuging as a gas). They centrifuged uranium to enrich it at the place I worked at until sometime in the mid to perhaps late 50's.

As to thorium vs uranium, it's true that thorium was abandoned because you can't weaponize it:

http://discovermagazine.com/2014/june/3-ask-discover

https://www.forbes.com/sites/energysource/2012/02 ... 6cb5ea1d80

Re: COAL Cogeneration

Posted: Mon. Feb. 11, 2019 9:41 pm
By: McGiever
Some electric utilities sold off some of their smaller and somewhat older coal generating plants to buyers who eventually converted those same plants into Natural Gas boiler/turbine/generators. Guess what? Now they, the sellers, are boo-hooing because they cannot compete with natural gas fueled generation. Sometimes it DOES pay to get your hands dirty. ;)