Making pellets from soft coal

Making pellets from soft coal

PostBy: Harvestfuels On: Thu May 05, 2011 12:44 pm

Hello, I am new to the boards and was wondering if anyone could tell me what they think of making pellet fuel from soft coal? I saw a guy make it before and was thinking it would be a great idea to use in stokers and pellet stoves. I just wonder if it would actually work the pellets were hard and durable but I did read some where in this board that soft coal swells and might clog the burn pot. Being soft coal is so much cheaper I figure if one were to start a pellet plant you could turn a profit and provide a alternative to over priced anthracite coal and wood pellets. Thanks Tony
Harvestfuels
 

Re: Making pellets from soft coal

PostBy: Berlin On: Thu May 05, 2011 1:14 pm

No need to start a pellet plant, soft coal is already available in a size called "pea stoker" commonly available at the processor between $100 and $200/ton. A size about 1/4-3/4" that's used in small stokers and works wonderfully. While soft coal fines are cheaper, the energy used to press them into pellets would negate any cost savings over buying the natural screened coal product. BTW, only certain soft coals swell and that information is readily available in the form of the coke button or "FSI" number between 0-9, 0 doesn't swell and 9 swells considerably. There are ample soft coals available that don't swell enough to cause any problems in a stoker. Soft coal won't "clog" a burnpot designed for its use. Coal burns too intensely for most of the poorly designed steel burnpots available with most pellet stoves, regardless if it's in pellet form or naturally sized small pieces.
Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal

Re: Making pellets from soft coal

PostBy: Harvestfuels On: Thu May 05, 2011 4:52 pm

Thanks for the reply, ok so soft coal will burn in stokers? I was told by Alaska stoves that they tried soft coal and it does burn but they had problems with it burning too fast I called them today. I just wanted to hear from others who tried it. I was looking into making pellets from soft coal and firing my mill on used oil to cut out fuel cost. Just thinking of a way to make cheaper fuel available.
Harvestfuels
 


Re: Making pellets from soft coal

PostBy: Berlin On: Thu May 05, 2011 9:16 pm

Soft coal burns very well in stokers. In fact, soft coal under ideal conditions actually achieves higher combustion efficiencies than hard coal in a stoker. The difference is that soft coal in smaller stoker applications such as residential and light commercial burns in what's called a single retort underfeed stoker. Because these are often built heavier and are correspondingly more costly, they are not often used for anthracite, although they work well for anthracite too; EFM, Van Wert and others use an underfeed stoker. Anthracite, unlike bituminous coal will burn well on an inclined grate type stoker with a pusher block, which, to save money and space, is what most, if not all, stoker stoves that burn anthracite use. Unfortunately, no one builds bituminous stoker stoves any more. Larger, 250,000btu+ stokers are available to fit into a boiler or forced air furnace of your choosing, but no complete package is built new today unless you go with an outdoor boiler stoker in the 400,000btu+ range. Having said that, bituminous stoker stoves, furnaces, and stand-alone stoker units are to be found from time to time on craigslist, ebay, etc.

My small bituminous stoker add-on furnace/stove:
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Size of bituminous "pea stoker" coal, average size, a dime.
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combustioneer model 77 stoker fire
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combustioneer hopper
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picture of a will-burt s30 stoker retort
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looking up into combustioneer heat exchanger while fire is stoking
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Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal

Re: Making pellets from soft coal

PostBy: Short Bus On: Fri May 06, 2011 2:08 am

Berlin,

Is that last picture a view of some sort of ceramic heat reflecter, above your fire?
Short Bus
 
Stoker Coal Boiler: Kewanee boiler with Anchor stoker
Coal Size/Type: Chestnut / Sub-bituminous C
Other Heating: Propane wall furnace back up only

Re: Making pellets from soft coal

PostBy: Berlin On: Fri May 06, 2011 10:06 am

Yes, it is. It is a piece of ceramic fiber combustion chamber material from an oil furnace. It eliminates any coke production and helps create denser clinkers. When the fire is burning it is glowing bright orange. It also helps reduce any soot production and allows the reduction of excess air from the stoker fire before reaching the soot point. Basically serves the same purpose they do in oil furnaces.
Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal

Re: Making pellets from soft coal

PostBy: rockwood On: Fri May 06, 2011 10:19 am

Berlin wrote:It is a piece of ceramic fiber combustion chamber material from an oil furnace.

Is it somehow fastened to the heat exchanger tubes or how do you have it suspended there?
rockwood
 
Hot Air Coal Stoker Furnace: Stokermatic coal furnace
Hand Fed Coal Stove: Rockwood Stoveworks Circulator
Baseburners & Antiques: Malleable/Monarch Range
Coal Size/Type: Soft coal: Lump and stoker (slack coal)

Re: Making pellets from soft coal

PostBy: Berlin On: Fri May 06, 2011 11:37 am

it is suspended by wire.
Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal

Re: Making pellets from soft coal

PostBy: Short Bus On: Fri May 06, 2011 3:21 pm

There is a store in Faribanks that sells some sort of universal fire box liner for oil burners to replace the originals, I'll try some of that above my burner see if I can make better clinkers.
The Idea has been kicking around in my head ever since a friend of mine was cleaning out his oil burner and realized he was breaking up and vacuming out a factory part of his combustion chamber.
Short Bus
 
Stoker Coal Boiler: Kewanee boiler with Anchor stoker
Coal Size/Type: Chestnut / Sub-bituminous C
Other Heating: Propane wall furnace back up only