[NAME:make
bessermer steel bars using BITUMINOUS Coal]
However the lining of the Bessemer reaction chamber was dependent on the impurities you face with your ores.
There is no passive or simple method of removing sulfur in particular using the Bessemer process. Early on, in fact, there was no method at all of removing sulfur, and you simply couldn't use it with sulfurous fuels (i.e. most coals). Only awhile after the invention of the process, they discovered some added slags and methods you can potentially add to increase ability to neutralize sulfur, but:
1) They are still of limited effectiveness, and they are very expensive and complicated. You have to get a bunch of calcium and/or magnesium flux first (extra reagents for you), then you have to inject them with a lance (more complicated building and skills), then you have to skim the slag which you can otherwise normally avoid as much, then you also end up ruining your lining (which also needs to be magnesium oxide rich and more exotic) which then has to be replaced, at expense and time.
2) Everything mentioned above is stuff you still would only consider doing AFTER coking your coal, not instead of it, if your coal has any sulfur in it (which most does). Because doing all of the above things is vastly more expensive per amount of sulfur removed than simply coking it. So you would still always do that first.
3) These methods would be rarely employed EVEN IF you only had high sulfur fuel, because there would always also be the alternative of a normal blast furnace. Blast furnace technology, although it uses more fuel, still almost always would save money with high sulfur fuels. This is because you can run a blast furnace in reduction, unlike a Bessemer furnace, which offers a much cheaper way of removing sulfur. So most of the time, if your only fuel was sulfurous, you'd just use a blast furnace and more fuel instead of fussing around with all the expensive magnesium nonsense. You would only ever use that if simultaneously you had very little fuel available AND it was sulfurous AND you had the magnesium available affordably.
(Or, perhaps more likely, if your only fuel was super high in sulfur, you just wouldn't set up shop at all, since you'd be unable to compete affordably. But I digress)
The Blast furnace was quite ancient, used in China around 2-300 BC, if you want to call it a blast furnace mod, just change the output to pig iron instead of steel. The Bessemer idea is to take the output of the blast furnace and blow air through it and then cast it into bars, If you can manage to do that with the molten output of a blast furnace you do not have to spend the fuel to reheat the charge
As noted in the above paragraphs, it's not "just" an issue of blowing some air in afterward. Blowing the air fundamentally restricts the chemical environment to oxidation, which significantly limits one's abilities to remove certain impurities affordably. This leads to a tradeoff between amount of fuel versus restriction on the necessary quality and purity of ingredients. Bessemer is less fuel intensive, but more ingredient pure (including fuel).
the small backyard blast furnace is quite ancient and hardly a bulk process
I'm talking about Bessemer. I admit I don't know why exactly, but numerous sources cite 3-5 tons final product as being the smallest Bessemer batch. It seems unlikely to me that this is a consistent market restriction, versus a chemistry one. Could be wrong.
Regardless, in terms of gameplay, I think the extra planning required to make 50 hauling jobs or whatever without your dwarf falling asleep in the process makes it a little more fun. You have to think ahead and make stockpiles right next to it, etc.