Petroleum coke vs Charcoal: Switch or nah?

[Joki]

Good day.
Having recently gotten into this hobby, i've stumbled upon a huge question regarding which fuel to use.
To add some context, my forge consists of a semi-truck's brake drum, filled with refractory concrete to make a bottom-blast firepot. For a blower, I have a simple hand-cranked blower.

For fuel, there only seems to be Petroleum Coke available for sale nearby, I tried searching for Bituminous Coal but there just doesn't seem to be any for sale, at all, here in Buenos Aires.
Now, I have bought and used Petroleum Coke, but i'm not sure if it's really all that good of a choice. 
Petroleum coke seems to be porous, hard to light, and it seems to ''break down'' into dust, which clogs up the grate and makes maintaining the fire rather messy. It also smells terribly bad (although I do wear a mask while forging). 

Something I've noticed is that there are two kinds of petcoke, as seen in the picture. The porous, turn-into-dust one is on the left, while at the right there's a small piece of ''nicer petcoke'' as I'll call it for now. It looks much smoother, and doesn't seem to turn into dust.
I've bought 40kg in the past (at about $2 per kg) and I'm almost out of fuel now, having contacted the seller, they mentioned that they no longer have porous petcoke for sale, only selling the ''nicer'' one at $3 per kilogram. The seller claims this ''nicer'' petcoke lasts twice as much as the porous one.

Charcoal, on the other hand, I have access to at a much cheaper price, about $0.4 per kilogram. This is hardwood lump charcoal, sold in 4kg bags at $1.6 per bag. While I know it has been used for blacksmithing for hundreds of years, I'm not having much success with it thus far; when using charcoal, it just seems unable to get hot enough, my pieces only reaching a red-ish color instead of the bright yellow petcoke takes them to. Is charcoal really that much ''colder'' or am I doing something wrong?

Now, what would be best? Do I buy 10kg of this ''nice'' petcoke that should last me the same as 20kg of the ''bad'' one, or learn how to properly use charcoal (even build a new forge that suits it better, if necessary?) for much cheaper? From what I understand, one goes through charcoal much more quickly than other fuels.

Note: This is my first post. I've read the ''Read this first'' section, do let me know if I made any mistake in formatting my post. 
Any feedback is much appreciated. I'll answer any further questions in case there's some information missing.
Thanks and have a good one.
 

[George N. M.]

Welcome aboard from 7500 feet (2285 meters) in SE Wyoming, USA.  Glad to have you.

Petroleum coke is 8-10,000 BTUs/pound (I'm not going to try to convert to joules/kilogram) and charcoal is about 9,700 BTUs/pound.  So, the heat value is about the same per weight.  However, there are other considerations.  First, your bottom blast forge is not optimum for charcoal.  Generally, a side blast, trench type works better for charcoal.  However, petroleum coke has a fair amount of hydrocarbons still in it and I don't think I'd want to be breathing the smoke, even with a mask, unless it was a pretty serious one with appropriate filters.

If you want to experiment with a charcoal forge inexpensively look up JABOD (Just A Box Of Dirt) forges.  Folk who have more experience than I have with charcoal for a forge fuel can offer more suggestions.

I think that if it were me I'd try the "nicer" coke, 5-10 kg. and see how it works before I made a decision to either buy more or convert to charcoal.

BTW, when I use my solid fuel forge I usually burn coal coke which I get from a farrier supply place.  You might check and see what farriers are using in Argentina and where they get their fuel.

"By hammer and hand all arts do stand."

[Irondragon Forge ClayWorks]

I have no experience with petroleum coke but have used lump charcoal in both my bottom blast and side blast forges. Like George N.M. said the side blast is better with charcoal. What I have found with charcoal is it takes a much lower air flow than coke. With my hand crank blowers, I have to turn them much slower, to get the maximum amount of heat, too fast and it seems to cool the fire. I have no trouble forge welding with charcoal, when I get the air flow right and prefer it when forging knife blanks.

I can't control the wind, all I can do is adjust my sail’s.
Semper Paratus

 

[Frosty]

The bronze caster member of our club runs the yearly iron pour at the "Art On Fire" (AOF) event. He uses a cupola melter run on Pet coke. Once it's burning properly there aren't any noticeable smoke or fumes. It smokes until it's going well but Pat arranged an air belt at the top so it burns smoke before much gets out, once hot he shuts the "after burner" off.

Pat usually has several large sacks of pet coke as AOF isn't the only place he pours iron. Anyway I tried it in my old rivet forge once and as advertised it's hard to get lit and the smoke is unpleasant. Once going I treated it like green coal letting it burn off the residual oils and whatever in the heart of the mounded pellets. That didn't stick together well enough I didn't have to constantly reshape it.

It got hot enough but was a PITA fuel. Perhaps more broken pieces like your "nice" coke would be more manageable than the smooth oblong round pellets I tried. They're about the same dia. and shape as round end of a CO2 capsule and half the length. 

It works once you understand the stuff, lots of guys use it but it's too much hassle for me. I'd burn charcoal but I have a couple decades experience using the coals in a campfire. It's like we're old friends. Be REALLY easy on the air and it lasts well enough, what I like best is it's very clean heat. Remember, Like Glenn was fond of saying, "it isn't the fuel that makes the heat, it's the air."

Frosty The Lucky.

[George N. M.]

I'll point out that coal coke is hard to start too.  I basically start a coal fire and feed coke into it to start the coke.  And coke, unlike coal, needs some constant air to it or it will go out.  When I am working on the bench I have to turn around every 2-3 minutes and give the blower a couple of cranks.  You have time to go into the house for a bio break or get a cold drink but not to eat lunch.  I have learned to get my forge work done and then do my bench work and not bounce back and forth unless it is absolutely necessary.  Coal is a much more forgiving fuel.

I have never used petroleum coke.  So, I don't know how it compares to coal coke.

I started using coke because I was in an urban neighborhood and didn't want coal smoke to be a problem for the neighbors.  I'm used to it now and only occasionally use coal.

I will also point out that coal coke will produce clinkers because that is dependent on how many impurities were in the coal before it went into the coke oven,

"By hammer and hand all arts do stand."

[Joki]

George, Frosty and Irondragon, many thanks for the replies. I've built a JABOD in the past, and will migrate to it if I can't get the charcoal to heat the steel in the bottom-blast forge. Soon as I have time, I'll try again, making sure to crank slowly so that the heat isn't ''blown out'' or the charcoal sparks too much.
I do have a question, though, what exactly makes a side-blast better for charcoal? Would a deeper firepot help mine perform better?

Today, two things happened regarding the fuels:
First, I've noticed I got the charcoal price per kg wrong; the bags actually weigh 6kg or 13.2lb, which takes the price down to 0.27 per kg. This means, the $30 that 10kg worth of petcoke would cost me, would buy roughly 18 charcoal bags, totaling 108kg or 238lb. Needless to say, this is an even better deal.

Second. The ''nice petcoke'' in the picture may not actually be coke at all; I paid a (rather reluctant to gettiing paid) local welder to make a flatter for me out of a plate and a hammer head I've prepared. The welder, a former blacksmith, decided to gift me a few of his old tools, including about 3kg worth of ''Rock coal'' as he called it. I don't know whether this is bituminous, anthracite or even coal coke; but some of the smaller chunks look just like the ''nice petcoke''. I asked where he got it from... and turns out it's pretty much stolen from cargo trains, then resold to and by local smiths and farriers, but this was many years ago, and he doesn't know where to buy more.

The coal I've been given today, small and large pieces. The small piece is about 5cm or 2 inches long. The larger chunk weighs 660 grams or 1.4 pound

Guess I'll use this coal until I run out. He did claim it ''should last me a long time'', we'll see.

[George N. M.]

Generally, coal will be shiney on freshly broken surfaces.  The higher the grade of coal (anthracite, high grade bituminous) the more glassy it will look.  Lower grades, sub bituminous, etc. will be less reflective.

Coal coke will be porous with lots of little holes/bubbles in it.

I did some research and Argentina produces very little coal domestically, about 2% of the country's consumption.  The other 98% is imported.  From where, I have no idea.

You should be aware that not all coal is created equal for blacksmiths.  It needs to be a good cooking coal and have few impurities (which make clinker).  The coal which is mined here in Wyoming is mainly used in power plants and is a pretty poor coal for blacksmithing.  It is sub bituminous but is low in sulphur which cuts down on air pollution.  Most good blacksmithing coal is called "metallurgical" coal and is used to make coke which is used in steel production.  So, if you have access to coal it may not be optimum to be used in a forge.  Like with unknown steel experimentation is often necessary.

And, yes, I used to be a geologist.

I think that a side blast is better for charcoal because it will go through the fuel and consume all of the oxygen.  A vertical blast may not use up all the available O2.

"By hammer and hand all arts do stand."