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[YelDohan]

Background
1. Where I come from, wood burning is a profession with a long history. I know there's lots of expertise involved in the production of high-quality charcoal.
2. I've seen a wood burning master spending days if not weeks on a single burning session. It doesn't make sense to have skilled wood burners produce charcoals faster.
3. It's annoying when one can't find a sedimentary layer and must cut and burn lots of wood for the metal industry.

Suggestions
1. Charcoal qualities. This not only lead to different price tags or affect the mood of a metalsmith using it, but can also have different levels of energy output.
2. Higher wood burning skill should result in higher yield of charcoals (or ashes) per wood, instead of faster burning time per wood.

I don't know anything about coke production, but I suspect it's similar.

[Carp McDwarfEater]

I could be totally wrong, but I was under the impression that charcoal is made from pyrolysis, not burning. Don't they just put the wood in an airtight furnace or something (so it can't burn) and then get it really hot? It doesn't sound like experience with that would allow you to somehow create larger quantities of charcoal.

I personally feel that higher wood burning skill=higher speed is better than somehow getting better yields (at least in the case of burning wood to ash) because it makes sense. If you know what you're doing and use kindling and stack the firewood in an efficient way, you can burn through a given quantity of fuel faster than if you just throw stuff onto the fire and practically smother it, like a novice wood burner might do.

[GreatWyrmGold]

Suggestions
1. Charcoal qualities. This not only lead to different price tags or affect the mood of a metalsmith using it, but can also have different levels of energy output.

Any basis in reality?

2. Higher wood burning skill should result in higher yield of charcoals (or ashes) per wood, instead of faster burning time per wood.

Well, a master burner should be so used to the system that he doesn't waste as much time as someone who's just starting to learn. I certainly don't think that faster burning time should be eliminated.

[wierd]

1) actually, yes. Good quality charcoal is hard, and shiny, with no remaining woody smells.  Poor quality charcoals produce soots and dont burn nearly as cleanly as good quality charcoals.

2) A charcoal maker balances burning some of the wood to make the heat to pyrolize the rest of his load, against the loss of that wood, since it could be charcoal instead.  An unskilled maker will waste much of the load with an inefficient burn, and produce less, and lower quality charcoal.  A skilled maker will burn significantly less, but gain considerably more of the load as charcoal.

Example-- A proper kiln design traps more heat than it allows to escape, so even a tiny heat source will eventually make an ideal kiln fire. (like a candle.) this assumes a perfectly refractory material, and a perfect flu design.  Those are both impossibilities, so we cant reasonably expect to fire a ton of wood into charcoal, using a candle flame. What we can expect, is to fire a ton of wood into charcoal using a hundred pounds or so of the wood, instead of half a ton.

When it comes to charcoal production, production that is slower is better.  Wood contains chemically bound water, which under the pyrolizing conditions of the kiln, will chemically combine with carbon, and produce "Syngas"- a mixture of reduced water in the form of hydrogen gas, and carbon monoxide.  This actively removes a fair chunk of the charcoal's mass if you dont control the reaction.  Firing the load slowly allows the water vapor to escape up and out the flu, before reaching a reactive temperature that would deplete the carbon of the load. Basically, you hold the kiln at about 420F, and just hold it there for a very long time. This drives off the water, but is under the kindling point of the wood, so it doesnt chemically combine with that water to form syngas. The slower fire doesnt need to be as big, since the kiln isnt kept all that hot. (It's just good pig roasting temps! BBQ!) Once the load stops gassing, you totally seal up the saggar, and heat it up to 450ish, and hold it there. Then the magic happens.  Usually, they pyrolysis of the wood itself is sufficient to keep the reaction going for the most part, so input fuel is actually reduced once the ideal target temp is reached. Keep it covered and insulated for a full 36 hours or so, until it cools.

unload, and enjoy your charcoal.

(That's the very simplified version. Skill and technique will have considerable effect on the quality and quantity of the finished load, just as the OP says.)

[Carp McDwarfEater]

I still doubt skill would make enough of an effect on the amount of fuel saved to justify you getting two or three charcoal instead of just one. But I suppose that your argument as to why there should be quality levels is valid.

[King Mir]

I think it's reasonable to have a skilled wood burner to produce more charcoal, but not higher quality charcoal. Quality in DF is reserved for finished goods, not raw materials, and I think this is a good system. Otherwise it would complicate the value calculation of finished goods, building, and other products, with little gain.

[GreatWyrmGold]

1) actually, yes. Good quality charcoal is hard, and shiny, with no remaining woody smells.  Poor quality charcoals produce soots and dont burn nearly as cleanly as good quality charcoals.

Interesting. How does this translate into better forging conditions?

-snip-

I am pretty sure that never actually answered the point I'd brought up...

I think it's reasonable to have a skilled wood burner to produce more charcoal, but not higher quality charcoal. Quality in DF is reserved for finished goods, not raw materials, and I think this is a good system. Otherwise it would complicate the value calculation of finished goods, building, and other products, with little gain.

Agreed. Of course, we'd need ways to turn partial bars of charcoal into full bars, but it could work.

[King Mir]

I think it's reasonable to have a skilled wood burner to produce more charcoal, but not higher quality charcoal. Quality in DF is reserved for finished goods, not raw materials, and I think this is a good system. Otherwise it would complicate the value calculation of finished goods, building, and other products, with little gain.

Agreed. Of course, we'd need ways to turn partial bars of charcoal into full bars, but it could work.

You could just have a certain probability of producing an extra bar of charcoal, that depends on the skill.

[NW_Kohaku]

Or a burning of charcoal could take more wood per reaction.  If you took a larger number of logs, like 3 logs to perform one production of charcoal, you could wind up with a broader range of charcoal without having to make a single log produce 3 charcoal, like ending up with 2 to 6 bars of charcoal from 3 logs.

That's mostly presuming the benefit of higher-quality charcoal would be that it burns more efficiently, and hence, you can use less of it, which in turn means a smaller bar is worth the same amount of energy.


On how long it takes, part of the problem with a lot of the workshop jobs is that dwarves stand at a workshop until a job is done, regardless of whether that actually makes sense for the job at hand. 

No brewer, for example, actually stands and watches the actual fermentation process.

Hence, the fact that it takes them less time to complete a burning job can just be stated to be unrealistic nonsense of an origin of the quirks of how DF is currently coded.  (There's also the fact that a trip from your house to the mess hall takes roughly 3 days, for example...)

[weenog]

Quality levels for charcoal seems amusingly dangerous to me.

A masterwork of Urist McBurner has been lost!
Urist McBurner cancels Make Charcoal - Throwing a Tantrum!
Urist McBlacksmith cancels Forge Steel Breastplate - interrupted by Urist McBurner.
Urist McBlacksmith has been struck down.

[10ebbor10]

To be fair, masterworks being lost only count for when they are not used for their intended purpose. Hence the fact that cooks don't mourn that the food they make is eaten.

[King Mir]

On how long it takes, part of the problem with a lot of the workshop jobs is that dwarves stand at a workshop until a job is done, regardless of whether that actually makes sense for the job at hand. 

No brewer, for example, actually stands and watches the actual fermentation process.

Hence, the fact that it takes them less time to complete a burning job can just be stated to be unrealistic nonsense of an origin of the quirks of how DF is currently coded.  (There's also the fact that a trip from your house to the mess hall takes roughly 3 days, for example...)

You're equating two very different failings in realism in DF.

It's true that workshops heavily abstract the task of producing items, and more jobs which have a waiting component would be more realistic. And I'd say it' be desirable; we do want brewery to be more realistic.

And It's true that the way time passes in fort mode is strange. Fort mode effectively has two time scales going on simultaneously, the year time scale, which the game reports, and the implied day time scale represented by how long it takes a dwarf to do a day's worth of tasks, like eat, sleep, and drink. It's a way to make interesting things like goblin invasions and caravans happen more often. The same technique is used in the Sims to make people grow up in a matter of days, and get promoted on the same scale. It's a good mechanic, and should not be changed.

[wierd]

Gold:

Sorry!  Better quality charcoals contain fewer impurities, which means artisnal steels produced using them for the smithing process will introduce less metal weakening agents, like sulfur compounds. This translates to superior quality metal craft goods produced from quality charcoal, vs from crappy charred wood bits.

High quality charcoal is essentially pure carbon, in line with coke. When burned, it produces almost no ash. The stuff you put in a BBQ grill is not quality charcoal.

High quality charcoal looks a bit like this:

Spoiler (click to show/hide)

When broken, the cleavage is highly reflective and lustrous.  Compare that with a charcoal briquette. Smell the bricquette. If it has any smell at all, it is not premium charcoal. Premium charcoal is what goes inside an aquarium filter pack, or in a gas mask.

You can test the difference between premium charcoal and a charcoal briquette yourself fairy easily:  buy a bag of charcoal BBQ briquettes, and a charcoal aquarium filter.

With a gram scale, measure identical weights of both substances, and light them with a butane lighter in a fireproof ceramic dish, and allow both to burn down completely.

Time the rate of burn, and when complete, weigh the resulting ash.

[kerlc]

On how long it takes, part of the problem with a lot of the workshop jobs is that dwarves stand at a workshop until a job is done, regardless of whether that actually makes sense for the job at hand. 

No brewer, for example, actually stands and watches the actual fermentation process.

Hence, the fact that it takes them less time to complete a burning job can just be stated to be unrealistic nonsense of an origin of the quirks of how DF is currently coded.  (There's also the fact that a trip from your house to the mess hall takes roughly 3 days, for example...)

Well, from what I understand, charcoal makers stood and watched the piles until they were done.

[wierd]

Of course! It's like running a wood fired kiln! You can't walk off and leave it. SOMEBODY has to stand around and keep the fire at the ideal temp for the task.

Leaving it allows the fire to ash up and die down, or to burn too hot if the wind picks up. Either one will jeopardize the load, in both cases. (Pottery kiln, due to thermal shock, and possibly overmaturation of the ware--- Charcoal kiln due to suboptimal pyrolysis conditions.)