‘Shrooms & char

Muschrooms & Biochar

Yesterday I visited Main Street Farms (MSF), a highly sustainable aquaponics operation that also includes high tunnels and mushroom production.  They are also hard at work learning how best to put worms & insects to work and have created an admirable agro-ecosystem which could provide a successful model for local food production in the Northeast and beyond.

What made the tour even more interesting were the folks there with me, two employees from a ‘combined heat & biochar’ (CHAB) equipment manufacturer and a very knowledgeable horticulturalist from Cornell. Our hosts graciously toured us around their facilities and showed us all of the different research projects they’ve been conducting over the past few years in an effort to become as sustainable as possible. Inspiring stuff to say the least. We are hoping to start a project using biochar production technology on-site which would enable them to become even more sustainable.

My role on the team is to uncover and quantify opportunities for possible biochar ‘interventions’, one of my favorite things to do! I had a number of different thoughts on how biochar could benefit this kind of operation but for today I’ll focus on the fungi! As I’m always on the hunt for underutilized biomass, I was delighted to see up close for the first time some spent mushroom substrate (SMS) from their oyster mushroom production. They had at least two different flavors; some made from sawdust & some from coffee grounds. I immediately asked for samples to test for biochar thinking I’d uncovered a novel new feedstock. When I had time for a quick tete-a-tete with Master Google I soon found out that my novel idea wasn’t so novel after all, others are on the case!

Turns out for every pound of delicious fungi produced, five pounds of substrate are needed, so there is a growing amount of this stuff around looking for appropriate end uses. The moisture content is pretty high (>60%) which can be a challenge for charring, but a CHAB unit could help with that.

After a mushroom flush (think harvest not toilet!) sometimes the substrate can be ‘dunked’ or rewetted to grow another flush. Apparently after dunking some growers ‘roll’ the substrate in vermiculite to increase water holding capacity. So another interesting possibility for biochar would be to roll the mushroom growing medium in biochar and get rid of the not very eco-friendly, vermiculite. Within an aquaponics system, I’m wondering if by dunking the substrate in the nutrient rich fish water, sufficient nutrients would be added back in to the substrate to provide for more flushes. Alas this is completely outside of my area of focus but still interesting to put out there for someone else to answer or research.

From a quick scan I also learned that SMS needs to be heat treated before it leaves the grow room to eliminate any pathogens before being added to compost or land applied. With a CHAB unit in the greenhouse, the heat could most likely be used for this purpose.

What I’m really wondering though, is whether biochar or a biochar blend could be used as a mushroom substrate. Surprisingly Master Google failed to deliver any interesting research or projects on this topic. If anyone has knowledge on this, I’d love to know!

Next up I’ll be casting about for biochar synergies for aquaculture!

CHARvest the Invaders!

Char the Invaders!

Make biochar out of invasive species

Today I read about how the NY DEC will be doing a controlled burn of 14.5 acres at a wetland to rid the area of phragmites australis (aka the common reed). Apparently this kind of controlled burn, also called a prescribed fire, is pretty common.   Little did I know (till this morning actually) that every year hundreds of thousands of acres are deliberately torched for a variety of reasons, from habitat management to wildfire control.   That’s a whole lotta CO2 going up in smoke, not to mention fine particulate matter which is no doubt aiding & abetting asthma!

I totally get the reasons for doing this, but I can’t help thinking that it’s a bit of a wasted opportunity.  Time for another biochar intervention me thinks!  Yes, charring would be far more labor intensive (read: expensive), but it would also be safer, less polluting in terms of air quality,  AND provide a by-product that could potentially enable increased bio-diversity and improved water quality. Heck maybe they could even sell the standing invading or diseased biomass to a biochar producer for a few bucks and have the biochar companies come in to ‘CHARvest’ the lot.  Seems like a fair trade to me.

There are already a few ways to convert invasive species or forestry slash  into biochar.  One interesting model is from Carbon Cultures, which looks something like a tent but acts like a mobile kiln.  Another option from down under is the CharMaker, made by Earth Systems Bioenergy. The char produced could be used strategically within the area charred to help rejuvenate soils or remediate any toxins.

A third option which offers interesting possibilities for areas that drain down into a body of water, might be do dig a ditch and burn the biomass in the ditch (see great ‘how-to’ post here).  Leaving the char in situ would help keep excess nutrients or toxins from polluting wet lands and other water bodies.

That food versus fuel argument sometimes bandied about to quench the hope for biochar is looking sillier and sillier…

The sweetest closed loop biochar model: maple sugaring with biochar

Maple Sugar & Biochar

Around this time of year my daughter’s school hosts a great event to teach kids about the old & new ways of tapping maple sugar trees to make maple syrup which includes lots of hands-on learning and tasting (YUM).  Having attended in previous years as a chaperone, my interest was piqued especially when I saw that burning wood is an essential element of making maple syrup.  This industry seemed ripe for a biochar intervention!

The mighty maple sugar tree, apart from adding gorgeous red color to the fall landscape and providing enormous natural capital as a keystone species in many New England and Mid-Atlantic forests, is one of the most highly regarded trees from an economic perspective.  The wood is valuable for furniture and flooring while the syrup provides a natural sweetener first tapped by Native Americans. The maple syrup industry in the US is <$125M and provides seasonal work for thousands. Sadly the maple sugar tree is under attack from acid raid, drought, disease and climate change in general.

Evaporators are the key to the sap-to-syrup alchemy.  Traditionally wood has been the fuel of choice for firing the evaporators.  Inefficient evaporators can use up to 1 face cord of wood to make 1 gallon of maple syrup so some producers are moving towards fossil fuel based evaporators.

Given that wood-fired evaporators aren’t all that different from some of the biochar kilns on the market, I think it’s time to tap into a biochar solution for the world of maple sugaring!  A little tweaking here and there would allow for a carbon rich by-product (yes, I’m talking about biochar!) from the evaporation process.  Biochar could be added to the soil around the maple trees to counteract acidification, help maple trees to manage drought better and through improving soil microbial activity, improve their ability to stave off certain diseases.

To add one more closed loop to the whole maple sugaring with biochar design, a recent CHARquaintance told me that he adds a little bit of char to his maple syrup for a double dip of goodness!  What a delicious & nutritious idea!

What other evaporators used in the food processing industry could we convert to ‘char-vaporators’ and build more closed loop or cascading biochar designs? Food for thought….

Ditch the Toxins in your French Drains

Carbon Calverts

While roaming more than one big box home improvement store this weekend in search of materials for V2 of Terra Pads, I stumbled upon a drain sleeve which is normally used as a fabric sock for perforated drain pipes for French drains.  Perfect for what I was looking for!  Then I noticed these weird things that looked like giant worms which turned out to be Styrofoam peanuts packed around a slotted PVC pipe with a Drain Sleeve around them.  “Perfect” for French drains or so the advertising claimed. [A quick bit of math told me that those packing peanuts didn’t cost peanuts as buying the sleeve + the PVC pipe would have only cost about $15 and the peanut piping was $49 for 10′ of pipe!]

Allow me to bring your thinking down into the gutter for a few minutes…

Of COURSE this got me to thinking about how to detoxify this whole peanut worm solution with, yes, you’ve guessed by now, biochar!  Obviously they are using the Styrofoam as a replacement for heavy gravel.  I don’t have a problem with 98% of that (since that much is air) but the other 2% of Styrofoam is a little off-putting for lots of reasons which you can read about here.  So my initial thinking was  that swapping out the toxic peanuts for biochar would not only provide a similar lightness benefit but it would also help filter the water of many of the toxins that might be found in the ground water from pesticides or other nasties.

Then I was scanning this intriguing little article called ‘The Fallacy of the French Drain’ which points out that geotextiles can suffer from ‘blinding’ once silt & clay particles clog up the nooks & crannies and then water is unable to permeate through it.  So the next round of my thinking is ‘let’s ditch the drain sleeve’.  Just surround the slotted PVC pipe with biochar and add topsoil.

Then I got to wondering how much do you really need that PVC pipe if you have a foot or more of pretty clumpy biochar or maybe varying grades of biochar.  Or perhaps we could create culverts out of carbon instead of cement or plastic?  Imagine how many toxins you could prevent from getting into local water bodies?  Imagine how many fewer chemical products we’d be making and buying?  Imagine how much carbon you could sequester if you did this for all building construction sites?

The planet needs a lot of carbon sinks and this one makes a whole lot of sense!

The Quest for a Biochar Taxonomy

Biochar Taxonomy v2

One of the hurdles biochar sometimes faces is that it often gets portrayed as the solution for everything.  I’ve now read enough biochar literature to be both impressed by its multifaceted abilities and yet knowledgeable enough to know that it is not going to be the solution to every problem thrown its way, especially since the word biochar covers an almost endless variety of products, some of which have no business parading around under the biochar banner.

Low tech multifaceted products are not uncommon.  There are countless uses for things like baking soda, vinegar, egg shells and more.  These don’t really need to be further classified as different flavors of each of these seems to be able perform the various functions to a similar standard.

All-encompassing words used to describe a basic structure or to describe a particular end use are also plentiful (e.g.  ‘tree’ or ‘plastic’).  These words are undoubtedly helpful in getting us to a certain level of understanding but often times we really need to know more than just the Genus (or should that be the ‘Family’ level in the taxonomy structure? Who knows!).  Biochar is one of those words and it is screaming out for its very own taxonomy. (Can’t you hear it screaming?)

This should not be confused with the efforts to characterize biochar which are moving along in various parts of the world thanks to the efforts of the International Biochar Initiative and the European Biochar Certification program.  However both of these voluntary programs are mainly focused on biochar used in soils.  Moving forward there appears to be a growing number of applications for biochar. Different characteristics will likely be important for the different end uses.  This is the notion of ‘Designer Biochars’ which one is beginning to hear more and more about amongst the biochar literati.

So Biochar community, perhaps it is time to start creating a ‘Species’ level for biochar so that we begin to clarify the biochar message a bit more, so that the benefits touted to consumers will more accurately align with the biochar being sold for particular end uses, and so that the testing done on the chars is appropriate for its intended end use.

Shall we do that by feedstock (e.g. manure char, woody char, etc.) or by production (e.g. high temp pyrolysis, gasified, TLUD chars) or by end use (e.g. remediation char, sequestration char, feed char)? Personally I’m a fan of the last one but I suspect there are a variety of opinions out there.  I am very curious as to what others in the industry think…


[Shout out to Thea Whitman from Cornell who first enlightened me on the analogy of how the way the word ‘biochar’ is used is similar to the way the word ‘tree’ is used!]

Biochar Step Wells

Biochar Step Wells

I was recently introduced to the concept of step wells while reading the latest issue of “The Intelligent Optimist”.  Step wells are magnificent manmade structures most commonly found in India.  These deep water wells sometimes contain thousands of steps and date back more than 2,000 years. Since part of my brain seems to have turned into biochar over the past few years [i.e. high carbon, adsorptive, sequestering all manner of charcoal trivia, etc.] the picture of course reminds me of the cascading uses of biochar concept, first articulated by the Ithaka Institute (download a great presentation on it here).

Cascading information was a familiar concept in my previous life in corporate America, but the idea of cascading uses was new to me.  The gist of the idea is that something can be used multiple times before it finds its ultimate end use or final resting place.  [It’s a bit like the notion of ‘trickle-down economics’ except biochar cascades actually make economic sense ;-)!]

As I’ve delved into the economic impact of using biochar within different agricultural settings, I am increasingly convinced that biochar cascades are the best approach to building a viable biochar market.  The current price of biochar is still relatively high which makes the business case a tough sell if you are ‘just’ using it to increase crop yield.  The math just doesn’t work for many cropping systems.  Let’s take corn and soybeans as a few examples since these crops make up a huge percentage of US farm land.  In a good year these crops will gross less than $1K per acre (e.g. CORN: 2013 average was ~159 bushels per acre * $4 per bushel = $632/acre; SOYBEAN 2013 average was ~43 b/acre * $9.50 per b = $409) after much hard work, increasing expenses plus the stress of watching Mother Nature throw all manner of curve balls year after year. Adding even one ton of biochar would not only wipe out profits, but it would turn profits into losses.  To break even, assuming you were able to find biochar at $600 per ton, you’d need to nearly double corn yields.  [Most studies show that far more than one ton per acre is needed for yields to increase in most soils.]  I wish it were otherwise but yield increase alone is not going to sell biochar, at least for most annual cereal crops in US soils (vegetables might be a very different story as is using biochar in severely depleted soils such as in Africa).

But with the cascade model, the economics of biochar begin to look very, very promising.  There are a growing number of biochar cascades that are only now being identified so this notion of a Biochar Step Well with multiple cascades which all ultimately lead down into the earth might be a great metaphor for creating a successful biochar industry.  Much work needs to be done to validate and quantify the benefits for each of the different cascades, but that is beginning to happen and I’m excited to be a part of it!

Torrefied or ‘Terra-fried’?

Torrefied or terra-fried

Recently I’ve seen a few articles that seem to be blurring the lines between biochar and torrefied wood, also called ‘bio-coal’.  These two products can pass for identical twins to the average consumer, but really they are only fraternal twins (like me!).

Why so?  Well basically certain physical and chemical properties are different due to differences in the production process.  Bio-coal is produced at lower temps (i.e. 200 – 300C) as compared to higher ones for biochar (i.e. 400 – 800C).  At temperatures below 270C the effect is basically to dewater the material which is really the main goal for torrefaction since the end use for this product is generally as renewable fuel. Of late there seems to be more talk of using it as a replacement for coal in electricity generation if the economics can work out (seems to be selling for <=$200/ton from what Master Google tells me).

[Allow me to jump on my soapbox for a moment here.]

Temperature has a huge impact on recalcitrance (resistance to decomposition), pore size, surface area, pH, nutrient content, volatiles, carbon content and more which are all important if you are using the char in the soil. Have a look at the figure below which shows this in more detail.  If consumers are looking for improved crop yield (not the only reason by a long shot…more on that in future posts) using biochar, then it is important to ‘know what you sow’ from a biochar perspective.

Temperature & Char

Renewable energy may be created during the biochar production process – some systems allow for the heat to be utilized and others do not. But biochar should not be considered as a renewable fuel! One of the primary end goals of biochar is to impede some portion of the carbon captured during a plant’s lifetime from returning to the atmosphere.  Burning biomass to ash doesn’t accomplish that goal though it is still a huge improvement over burning coal or any other fossil fuels.

[Jumping off soapbox now…]

Biochar & Landfills

Biochar & Landfills

Recently I saw an interesting article about the potential of biochar to reduce the amount of waste filling up landfills.  The focus was on how waste generators or haulers could reduce tipping costs which are poised to increase as old landfills close and new ones are often much further afield as few people want them in their backyard (hello NIMBY!). Cost reduction is one of the biggest motivators for companies and individuals to become more sustainable. Who doesn’t want to save money, right?  And in this situation the business case for biochar use at landfills seems almost ridiculously easy to make for landfill operators.  I won’t waste another moment shedding light on this great closed loop biochar model.  Here’s my thinking:

Let’s say the landfill operator invests in some state-of-the-art pyrolysis equipment (one example here which actually generates electricity) so that they can continue to accept yard waste (which is being outlawed in a number of states due to the scarcity of local landfill space).  Not only can the yard waste tipping fees keep adding to their coffers but it could be converted into biochar which could be used as a very effective ‘daily cover’.  The federal government requires landfills to apply a 6” layer of daily cover which is meant to reduce pathogens, fires, flyaway garbage and lest we not forget the lovely aroma that often wafts away from overgrown rubbish piles.  Landfills use a variety of different materials for daily cover depending on availability, cost and local regulations. Substituting biochar as a daily cover could be advantageous for all sorts of reasons.  The University of Illinois has been studying the ability of biochar in landfills to suppress methane with promising results so far.

Other researchers are studying the ability to use biochar to clean landfill leachate in microbial fuel cells.  Early results show activated carbon to be more efficient, but I suspect there are ways to tweak the biochar production parameters or the biochar could be magnetized to improve the filtration capabilities of biochar.  This could be a huge savings as some landfills end up having to ship leachate off to a waste water treatment facility if they cannot process it on-site.

Perhaps the most interesting one for those that live in the vicinity of landfills is the ability of biochar to suppress “l’eau du dump”, that unforgettable smell that permeates neighboring air.  Using biochar as a cover material would likely substantially reduce the amount of sprayers that some landfills use to mask the nasty odors (what is in that stuff one wonders?).

At the end of the landfill’s active duty, biochar could also help with re-vegetation, something that can be problematic or at least expensive in some areas. Last but definitely not least in the benefits equation, is all that carbon that landfills will be able to sequester.  While it may not be worth money yet in the US, the day when biochar is a viable carbon offset is coming!

Charfait anyone?


There are biochar aficionados and then there are the ‘cHardcore’ biochar aficionados.  I used to think I was in the latter category, but apparently not. Recently the CHartist informed me that he consumes biochar with yogurt on a daily basis.  Not long ago another biochar buddy told me that she is a char chewer AND has started to brush her teeth using biochar.  Suddenly I felt that I just might be missing out on something really good here.

Although I am aware of many of the benefits of feeding biochar to animals, and I know that vitamin shops sell activated carbon for humans, for some reason I just hadn’t taken this next step on the char ladder. Could this one minor change to eating habits be one small step for mankind and one giant step for the planet?  I admit that is too big a question for me to answer in one small blogpost but still something to ponder!

It’s not that I am a total char ingesting virgin mind you. The Biochar Knight was kind enough to bring biochar covered peanuts to the 2013 Biochar Symposium so I had a little nibble there (I’m very curious as to whether this combo would make nuts safe for those with peanut allergies!). But biochar in my yogurt?  This morning I took the plunge (ok really I just dipped my toe in since I only ate one spoonful!) and I have to say, well, my puppy and cat loved it! Me, not so much.  Perhaps it was the size of the biochar I used.  The ones pictured in the (heavily doctored) pictured above show biochar made from cherry pits and boy were they crunchy. Next time I’ll have to try some biochar which is more powdery – like biochar made from coffee chaff.

Of course I had to google around to learn more about the benefits of ingesting charcoal or activated carbon.  Although it is definitely not a new practice, one of the questions that occurred to me was whether it could help with the bioaccumulation of certain metals like mercury which seems to be increasingly prevalent in the air, in rivers and in some of the sea food that we eat. Or could it help purge the accumulation of the arsenic that is increasingly being ingested via apple juice or rice. Both of these seem to be in the news a lot more recently and few treatments seem to be available and the treatments that are available seem to be costly.  How fantastic would it be if some kind of ‘Charfait’ product could sit along-side the pro-biotics that can be found more and more in our grocery stores?

Methane Rising: Can Biochar Help?

Methane Rising

Methane (CH4) has been in the news of late.  Seems that everything from flatulence to fracking is contributing to the precipitous rise in CH4, which is more than a tad frightening given that it has 34 times the warming potential over 100 years as compared to CO2.  The only good news is that methane doesn’t last long in the atmosphere (8 – 12 years) so if we get our act together we could correct the imbalance in the near future.

Mother Nature and mankind both belch out CH4 but the ratio has definitely tilted more heavily towards anthropogenic sources.  It seems unlikely that biochar would be able to positively impact Mother Nature’s emissions which largely come from Wet Lands or termites (but who knows, maybe if biochar could somehow be added to the termite diet it could reduce emissions!).

Emissions attributable to we humans is another story – there is LOTS of potential for biochar to allay the methane malaise. As I’ve mentioned in an earlier post, biochar + livestock is a love connection in terms of reducing methane emissions related to ‘enteric fermentation’ (i.e. burps, etc.).  While the amount of CH4 produced by livestock varies depending on a number of variables, adding char to feed shows promise in significantly reducing toxic burping.

Landfills, which are the 3rd largest source of manmade CH4 emissions, are also ripe for biochar as a means of abatement.  Recent research has shown that certain types of biochar, particularly char with high porosity, small particle size and low ash, can help reduce CH4 emissions.  [I’ll dive deeper on that topic in a future post as I think biochar & landfills is a natural combo for many reasons!]

The combination of manure management & biochar is already happening in a number of different ways.  Some companies are turning manure directly into biochar.  Other research is looking at combining biochar in anaerobic digesters fueled by manure.  Still other research has demonstrated that composting manure with biochar can reduce CH4 emissions.

Similar to manure management, wastewater treatment could likely benefit from biochar but I haven’t gone down that path too much as I suspect some of the heavy metals in wastewater treatment could render the biochar unattractive to end users so finding a market for the char could be problematic.

The US doesn’t have lots of Rice Paddies, but these are another source of methane.  Though I haven’t come across any research on biochar’s impact on CH4 emissions, the use of biochar in rice fields has been shown to reduce nitrous oxide (N2O), yet another GHG, in rice fields!

Overall, not a bad outlook for using biochar to reduce manmade GHG emissions!