5 Ways that Biochar is Different from Charcoal

I cannot tell you how many times I have heard, “Bio-what?

Biochar. Think biological + charcoal = biochar. Pretty simple.

Is biochar just charcoal? Can I just go buy myself some King’s briquettes and add those to my garden?

Short answer: NO. Emphatically no.

Biochar and charcoal are technically two different things. Here are 5 things that elucidate those important differences:

1. Definitions. 

Words, and what they mean, matter. According to the International Biochar Initiative (IBI) recently released Standardized Product Definition and Product Testing Guidelines for Biochar That Is Used in Soil, biochar is:

a solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment.

They go on to say that, “biochar can be used as a product itself or as an ingredient within a blended product, with a range of applications as an agent for soil improvement, improved resource use efficiency, remediation and/or protection against particular environmental pollution, and as an avenue for greenhouse gas (GHG) mitigation.” (this is not part of the definition, but I wanted to include it so you get a better sense of how cool biochar is.)

According to Merriam-Webster, charcoal is defined as:

a dark or black porous carbon prepared from vegetable or animal substances (as from wood by charring in a kiln from which air is excluded)

Vegetable or animal substances.

I have some bones to pick with the IBI Guidelines and their definition—I think it falls short of laying the framework needed to ensure sustainable, high-quality, environmentally beneficial biochar; and I think their definition is actually way too close to the definition of charcoal. But that’s me. And I’ll go on here to suggest some additional criteria that make biochar different from charcoal, IMHO.

2. Suitability as a soil amendment.

In order to be called biochar, it must be suitable (and therefore safe) for use in soil. Commercial charcoal is not going to necessarily be good for use in soil. Some of it may be. Some of it may not be. Many commercial charcoals are petroleum-based (not something I want in my veggies…though I do love the smell of gasoline. Total non-sequitur, but really, what’s up with that?) The charcoal that is leftover in your campfire is more likely to be good for use as a soil amendment than the stuff you buy off the shelf.

3. Sustainably produced.

As far as I’m concerned, if you’re going to call it biochar, it sure as hell better be produced sustainably—meaning that it comes from waste biomass, or sustainably harvested biomass. I think there should be a standard that says you couldn’t go cut down a forest to do this (annnnd, we might just go ahead and make that happen.). (fortunately, for now, the market conditions for biochar dictate that it’s highly unlikely that deforestation for biochar would be profitable).

Charcoal production is classically an unsustainable trade, and one of the biggest drivers of deforestation, particularly in developing country contexts. Commercial charcoal products, as I mentioned before, are often petroleum-based—another unsustainable, unrenewable resource.

4. Socially responsible. 

Biochar should also be socially ethical. It should create living-wage jobs for skilled trades and laborers alike. Biochar company cultures should be based on transparency, providing employees with autonomy and responsibility. Biochar companies should consider their wider impact on society, on the local communities where their projects are based.

I don’t know the in’s and out’s of the charcoal business particularly well, but my sense is that CSR (Corporate Social Responsibility) is not something high on their priorities lists.

5. Chemically different.

A charcoal product is going to be optimized for its energy value. This means that factors such as fixed versus labile carbon are going to effect is market value differently than for biochar. A high quality biochar product should have a high fixed carbon content (meaning it will stay in the soil for a long time), minimal tars (which are more acceptable, and perhaps even useful, in a charcoal-for-energy product), and a high surface area (giving lots of space for those little microorganisms to create their homes)—thus making it far more porous than charcoal.

Charcoal, on the other hand, should burn. That’s it’s main purpose.

And that about sums it up nicely. Charcoal should burn. Biochar should come from a waste material and be produced in a sustainable, environmentally friendly manner by happy people and clean technology in order to create homes for microorganisms, build soil carbon, absorb water, adsorb nutrients, aerate soil, break up clay, and create a healthier, more robust soil economy for healthier, more robust plants and healthier, more robust people.


Agree? Disagree? Have something to add? I welcome your comments!



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