Making pellets from soft coal

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

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.

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.

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:

Berlin,

Is that last picture a view of some sort of ceramic heat reflecter, above your fire?

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 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?

it is suspended by wire.

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.