I do blacksmithing as a hobby and use a coal forge. How much damage am I doing to the environment? I use bituminous coal and the forge is probably lit around 4-5 hours a week.
ETA: The forge is about 16" in diameter.
Fossil fuel; adds to your carbon footprint. A more useful measure would be about how many pounds of coal you burn in any timeframe - maybe an average week or month?
A friend of mine was a hobbyist blacksmith for many years (and ran a blacksmith shop at the local Renaissance Faire); I did some smithing with him from time to time. The above feels like the right answer to me. Compared to a coal-burning power plant, or even a diesel truck, I suspect that your impact is small, but non-zero.
My friend eventually built himself a gas-fired forge, which ran on propane, IIRC. If you’re really concerned about your carbon footprint, I suspect that propane might be a cleaner fuel source, though it’d require building a new forge.
100 lbs of coal will typically give you roughly 40 hours of forging, according to some highly accurate number I randomly pulled out of The Google (ahem… ok not the best cite, but let’s run with it). At 5 hours per week, you would therefore go through 100 lbs of coal in about 8 weeks and your total coal usage per year would be about 650 lbs per year.
For comparison, I used to work in a coal fired power plant many years ago (ok, many decades ago, dang I’m getting old). According to the power company that owns it, that plant burns a bit over 6 million tons of coal per year.
So if there were about 18 million blacksmiths working like you, all of you together would equal one coal fired power plant.
Power plants also have scrubbers that remove most of the particulate and sulfur emissions. Your forge has none of that, so it would only take about a hundred thousand or so of you blacksmith types to put out the equivalent particulate and sulfur emissions from a typical power plant.
Or to put it another way, they could reduce emissions from coal fired plants by 99.99 percent and you blacksmith types would still be statistically insignificant in the grand scheme of things.
It seems to me that the relevant comparison isn’t one blacksmith vs. one power plant-- Of course the power plant is going to pollute more. The fairer comparison would be one blacksmith vs. one person’s share of a power plant.
From Google, it looks like a typical American uses about 10 MWh of energy per year, with coal being worth about 2 MWh per ton, so a typical American is responsible for about 5 tons of coal per year, or about 15 times the amount engineer_comp_geek estimates for forge usage. So blacksmithing isn’t an overwhelming increase in your footprint, but it’s still a detectable amount.
… mining the ore … transporting … smelting …
Less than your car, but more than you exhale … maybe use anthracite coal instead …
Thanks for asking this question. I have been considering getting into blacksmithing and have been concerned about adding to my carbon footprint. I found a calculatorand based on a random guess of 24 barbecue tanks of propane per year (which would be really high) I would need to plant .3444 trees to offset my potential future hobby.
Plant 5 trees and I can rest somewhat assured.
Would using charcoal be an option, and would that lower the carbon impact since it comes from trees rather than the ground?
Just out of curiosity:
What kind of coal do you use? For some bizarre reason, I remember this from grade school - hard coal is ‘anthracite’, much cleaner and hence more desirable than soft coal ‘bituminous’, which burns faster and produces much more crud.
I also heard that anthracite was “commercially extinct”.
Did somebody find a new source?
It is
Yes. It’s still releasing carbon that was trapped in some form (if it had been left as wood) back into the carbon cycle, but less of an impact because it’s only shortcutting the tree->fall->rot or tree->harvest-wood->Ikea->landfill->rot cycle (unless that particular tree was destined for a fall->anoxic burial scenario, in which case it’s a wash, but statistically that’s not really significant nowadays)
Carbon offsets are about $10USD per metric ton of CO2. 270kg/600lbs of pure carbon converts to 1 ton of CO2. So for every 100lbs of coal you use, spend a dollar on carbon offsets and you should be easily carbon neutral. More concerning is probably the SO2 and PM2.5 that you’re pumping into the atmosphere. How dense is the area surrounding your workshop? If it’s in a city, you might contribute some small chance to someone developing lung cancer or heart diseases. If you’re out in the middle of nowhere, the damage is much lower.
I don’t know the state of anthracite supplies but it’s not going to be ideal for blacksmithing. It’s much more difficult to ignite and use in small quantities. A smith with a small forge will be frequently pumping air to increase the heat and then letting it die down while he works the heated metal and anthracite won’t react to the changes as quickly as the softer coal. It does burn hotter though. Coke is an alternative that is nearly pure graphite just like anthracite though not quite as dense. I think it might have the same problems for small forges and I don’t know if it’s produced in the quantities it used to be either.
Not sure if the 2 MWh per ton number is moisture free basis (it usually is). Pretty sure engineer_comp_geek number includes equilibrium moisture. So the 5 tons number is most likely higher especially considering that most power plants use sub-bituminous coal
My blacksmithing friend switched from coal to coke, before he built the gas forge (and also used coke for the forge he had at his blacksmith shop at the Renaissance Faire). Coke was more difficult to get lit, and needed more air to keep it lit – we used a blower to give the coke fire constant air, and then a bellows to add additional air as needed. Without the blower, keeping the coke fire lit was possible, but a lot of work on the bellows.
At that time (1990s), he could buy coke from a company in Indiana, though they weren’t accustomed to selling it in the small quantity he wanted.