How the sea can help rebalance C


This week I happened upon some fascinating biochar research focusing on charring seagrass wrack as a more sustainable means of disposal.  Not only is this environmentally preferable as compared to landfilling it, which causes all sorts of GHG emissions from the decomposition stage, but in all likelihood it could be economically better too.

Let’s discuss climate change mitigation potential first.  The reports states that in a mere 9.5km of Kenyan coastline, 6.8M kg of seagrass (dryweight) carpets the coast on an annual basis.  In their research they achieved biochar production yields of 48 – 57% which is actually pretty astounding and definitely not the norm with most current biochar production technologies.  (They did pulverize the seaweed prior to pyrolyzing so that likely provided increased yield.)  Still for conservative calculations, let’s assume 25%  biochar yield which is far more common.  Using the low end of the carbon content range they found for seagrass of 34.6%, this one small stretch of beach, which is less than 1% of Kenya’s coastline, could sequester more than 2M kgs of CO2e per year – not including calculations for reducing methane emissions from rotting wrack! 

Now on to economics.  Imagine how places like Kenya could benefit from creating sustainable jobs, cleaning up coastlines and possibly even becoming a carbon negative country by carbonizing excess seagrass! On the cost reduction front, the article states that one coastal town in Australia spent more than $28M for wrack ridding in just one year.  While there is a cost to collecting, handling, possibly drying and pyrolyzing seagrass, if mobile units could be taken to affected beaches, costs would most likely be lower, especially if carbon offsets were available. 

Seagrass is not the only excessive bounty from the sea that could be carbonized. Seaweed, an algae that grows 30 – 60 times faster than most land-based plants, is becoming ever more abundant due to fertilizer abuse (amongst other reasons).  Countries around the world that depend on beach tourism are increasingly beleaguered by odiferous mountains of Sargassum seaweed and kelp.  This too often gets carted off to landfills or buried in ditches at great expense, largely born by hotel chains or governments. Carbonizing fast growing seaweed could be a very efficient and relatively low-tech way to rebalance carbon levels and meet CO2 reduction targets while solving other problems that can depress tourism income.

A challenge with this particular type of biochar is likely to be the (relatively) high salt content.  For that reason it may not be ideal for use in certain soils.  However, it could be used in other ways that might help island or coastal communities to adapt to climate change.  Bagging it and piling it up to create artificial dunes could help when storm come and waters rise.  Using it as a construction material for sea walls might be interesting.  Perhaps it could be briquetted and used as green charcoal to reduce deforestation.  Incorporating seachar into salt licks for livestock might even be worth testing.  The point is, uses can be found!

I can’t even begin to calculate what the overall carbon mitigation potential is for all of this excess sea-based flora, but it is, as one of least palatable presidential candidate’s in US history would say, HUGE!

2016 USBI Biochar Conference Recap


The 2016 USBI Biochar Conference flew by in a flash this week.  It was great to see old friends, meet so many folks that I’ve corresponded with but never met in the flesh and to see so many new people that are joining the biochar fray. Academics mingled with industry, government representatives (USDA NCRS and Forestry mainly) chatted with NGOs and Venture Capitalists; Idealists focused on reversing climate change spoke to pragmatists focused on building the next big industry; Newbies met with the biochar literati and technology promoters exchanged ideas with agronomists.  Beyond those from within the US border were attendees from Canada, Mexico, Guam, Norway and South Africa (and probably other countries as well but those are the ones that I met).  It truly lived up to the ‘Synergy of Science and Industry’ theme.

Conferences like this tend to be like a smorgasbord – where there is more than a little something for everyone.  Hors d’oeuvres in the form of table displays showcasing various pre-production & pyrolysis technologies (I was particularly impressed with Forest Concepts “Crumbles” technology) as well as some other non-traditional technologies where biochar is part of an overall system (check out this amazing Algae Aqua Culture Technology).  Biochar producers brought samples and new products which I always love to see (and take!).

Also on the menu was an abundance of biochar presentations – nearly 90 in all.   Presentations were categorized into 4 subject areas: Agriculture/Horticulture, Forestry, Policy, and Stormwater & Remediation. Many of the presentation slides will be added to the USBI2016 website in the near future, so if you are interested in exploring a particular topic a bit further, check that out next month sometime.  I was particularly impressed with the sessions I attended in the Stormwater & Remediation track.  There is so much positive news coming out of that arena in terms of regenerating mine lands as well as using biochar to filter different waste streams.  Several folks are working on the sewage/biosolids and biochar front – both academic but also in terms of production technologies that can deal with high moisture content feedstocks such as biosolids.  Since I just recently wrote about this topic in the Biochar Journal, it was great to find and chat with others focusing on this endlessly renewable waste stream. 

Though there has been a burn ban on in Oregon due to the drought, a few folks did bring some small scale production technologies to display at the conference including a very nice version of the Kon-Tiki kiln, a funky pyramid kiln with the ability to flare off syngas (a new one for me), a rather fancy TLUD, and a little biochar bar-b-que (forgot to take pictures!)

Against the gorgeous backdrop of Corvallis and OSU’s campus, the ambiance, the knowledge sharing and the vibe was really great at this Conference.  Sincere thanks to all of the organizers!


Towards a Biochar Ethos

rhetorical triangle

Jonathan Shapiro’s book “Lawyers, Liars, and the Art of Storytelling: Using Stories to Advocate, Influence and Persuade” has a great perspective on ethos as it relates to Aristotle’s rhetorical triangle.  The biochar world would be well served to understand his thinking.  Ethos is often used to describe beliefs or ideals that define a community. In the context of Aristotle’s rhetorical triangle (i.e. ethos, logos, pathos), ethos refers to credibility.

Credibility can be boosted in many ways.  Clothes credentialize cops, cadets and candy stripers.  Certifications credentialize professions and products.  Testimonials, if provided by respected authorities, can also boost credibility.  Shapiro calls this ‘ethos by extension’.  Oddly enough he then adds “The field of expertise almost doesn’t matter.” This conflating of relevant expertise is something I see in the biochar world fairly often, yet I can’t quite bring myself to agree with Shapiro.  While it might work in a courtroom, I can’t say that is works in corn fields!

The biochar world has all manner of “experts”: agronomists, engineers, business people, climate scientists, farmers, environmental activists and more.  Each brings their own perspective, their own priorities and their own passions to the table.  Yet the question of who is most credible is critical.  It will determine who lives or dies, not only at the company level but for the industry as well.  [I could go on to say quite possibly for the planet as well, but that would likely lower my credibility in the eyes of many!] The question for the biochar community and more importantly for future buyers of biochar, is who to trust when they are talking about biochar? Whom do you trust before you incorporate massive amounts of the stuff permanently into your fields; fields which provide sustenance for you family, your community, and food security for us all. 

This is not a trivial or rhetorical question, nor is there a simple answer.  Scientists are often pushed to publish only positive requests if they want tenure.  Businessmen may take advantage of a lack of scientific understanding by the buying public and make extraordinary claims, perhaps unproven, about performance or may claim that only their product is safe.  Neither of these scenarios helps to build ethos for the individual nor for the industry.

For the biochar industry to succeed, we must take the other path outlined by Shapiro.  Instead of taking advantage of the confusion caused by a new and complex product, we should aim to enlighten and educate.  We should not attempt to sell biochar to everyone everywhere, but to sell the right kind of biochar and/or production technology to the farmer (i.e. ‘the audience’ in Aristotle’s parlance) whose specific constraints it can alleviate.  There are many ways to position biochar, but understanding what is most important to your audience is key to any selling effort. That is a much taller order, a much longer sell, and requires much more than just slick marketing of products with broad generalizations of the potential benefits of biochar.  But in the end, this additional effort will enable biochar to succeed and will facilitate word of mouth selling amongst satisfied customers which at the end of the day is what an industry needs to be truly sustainable. 

Time to update the Food Waste Recovery Hierarchy!

food hierarchy

The US EPA created the Food Waste Recovery Hierarchy (FWRH) in an effort to divert various organics towards the highest and best end uses. Sadly an inordinate amount of food waste, roughly 65% of the total waste stream, still ends up getting incinerated or landfilled.  Both of these disposal options waste valuable nutrients and landfilling organics generates CH4 which contributes to climate change. Newer technologies are evolving that can harvest nutrients and prevent emissions and even sequester carbon.

The New York State Pollution Prevention Institute just rolled out an updated Organics Resource Locator, a great resource to identify what and where various organics are produced. The database is meant to facilitate connections between producers of various underutilized organics (e.g. Food Processors, Restaurants, Institutions, etc.) with those that might want to use them (e.g. Compost facilities, Anaerobic Digestion operators, Food Banks, CAFOs, etc).

Wherever possible food waste can and should be diverted to feed humans and livestock. However this is often difficult to manage if proximity to end users with a consistent need for a particular kind of food waste is lacking. Sorting and transportation are often costly and time consuming as well.

Anaerobic digesters (AD) can take certain kinds of organics and convert it into energy but ADs can be finicky and require a balance of various inputs in order to work efficiently.  There is also a significant amount of high moisture digestate that remains at the end of the AD process.  Composting is a good option but operators often don’t want dairy, meat, fish or oils or any foreign objects mixed it.  It can also be constrained by seasons and by the need to balance carbon and nitrogen levels.

Carbonization via pyrolysis or gasification could be a very viable option for certain types of organic waste streams.  High moisture content (i.e. >25%) and heterogeneous waste streams have traditionally not been a primary target for feedstock for biochar. Carbonizing this kind of waste can be very difficult and often results in char which is low in carbon, with low surface area and potentially high salinity – not the greatest kind of char for soil amendments if you are looking for yield increases.  However a recent study from Singapore showed that gasifying blended food waste & woody biomass could produce high quality biochars that can be used effectively in nutrient poor, acidic soils.

Other waste streams which are more uniform and less seasonal could make for  more attractive carbonization targets.  Take the recent surge in craft and micro-breweries as an example.  Each brewery has to find an outlet for their spent brewer’s grain (SBG), a high moisture and high protein residual from the brewing process. Breweries in rural areas happily provide this to cattle or pig farmers that are willing to pick it up, but that is less feasible for urban brewers.  I am currently involved in a project focusing on pyrolyzing SBG which has recently been trialed rather successfully (see pictures below) once it was mixed with dryer feedstock to reduce MC.  Overall the char came out looking very nice though we are currently putting it through its paces to understand optimal end uses for high temperature SBG char.  Updates on this front will be presented at the Biochar 2016 Conference in August so I hope to see you there!!

SBG Char

Biochar for Mercury Detox?

charcoal smoothies

This weekend I tabled at a local event to keep spreading the word on biochar.  A woman came up and was simply gushing about biochar so I asked her why she was so enthusiastic. Most people that have ever heard about it in my neck of the woods are either gardeners or farmers, but that was not the case here.  She told me that she’d been suffering from mercury poisoning for a long time, had tried many different treatments to no avail.  Finally a holistic medical practitioner asked if she’d be willing to try biochar as a detox option.  Having been told there were few possible side effects she was more than willing to give it a go.  The prescription was to take small doses for 3 days, then wait 3 weeks and take another round for 3 days.  Blood work was conducted before and after and the biochar proved to work amazingly well.  She was happy and finally healthy.

Feeling a bit incredulous that a local medical practitioner in the Finger Lakes would know about biochar, I asked if she meant activated carbon or actually biochar.  She said, yes, it was definitely biochar.   Knowing that biochar is still uncommon in the Finger Lakes, I asked her where she bought it.  She told me the name of a local woman that I had sold a small amount of biochar to last year who wanted to test it on a few dairy cows that were not fairing too well.  Although I was hesitant to sell her char for this purpose as I’d not tested my chars on cows, eventually I provided her with a char that I felt would be safe and have relevant properties for that type of use. I’m pretty sure that is the char that ended up cleaning up the mercury for the woman that told me the story.  Never in my wildest dreams would I have thought of selling it to someone for human consumption without further testing – to date its mostly been tested for filtration purposes and has done quite well.  Turns out however, it was highly successful at sorbing mercury and a pretty cheap cure at that – at least in this scenario.  I am still smiling after hearing this story.  More investigation is surely necessary, but in a pinch I’d have to say I would definitely take this particular kind of biochar (made from grape seed extract which is a bit hard to come by unless you happen to know someone making grape seed oil!) to detox. 

Biochar: “Tiz bit dear”

Tiz bit dearThe question of how to price biochar has come up many, many times in conversations over the past several years.  While there is no perfect answer, I would argue that the current price is still too expensive for biochar to become widely used.  Apparently SouthDevonGardener would agree!

Focusing on biochar’s use as a soil amendment there are a few major questions that need to be answered to come up with a price that will spur the market: 1) who are you selling to and 2) what other products are you competing with and what do those cost?  The question of target markets for soil amendments is pretty straight forward.  There are three basic categories: gardeners, the “green industry” and farmers. 

The gardening market is often biochar producer’s favorite category as gardeners are not generally focused on making a profit off their small plots so their price tolerance is generally much higher than other potential buyers.  The downside is that it is a much smaller market overall and volumes purchased per transaction are very small.  This $7.6B market is large and growing, but there is a lot of competition for soil amendments and a lot of big name players dominate.  While some small biochar producers may do quite well selling biochar locally, at a national level this is a tough market to penetrate for small producers.

The price for other soil amendments that biochar could displace within the gardening market should play a role in setting an attractive price for biochar.  To some extent it does – at least when sold in smaller packages (e.g. quarts or gallons) when compared to peat moss, perlite or vermiculite though not so much when compared to potting mixes which make similar claims to boosting plant growth that biochar producers tout.

Pricing biochar

Here is a quick look at biochar prices on Amazon as compared to a few other soil amendments (I’m not a big fan of buying any kind of soil amendment on Amazon – but it provides for easy comparisons!):

Price comparison

Within the larger ‘green industry’ (~$130B) is the $20B greenhouse, nursery floriculture industry which could be a good recurring buyer for biochar.  However selling to this industry is a tad more challenging as they are much more savvy about soils and specific plant needs than many in the gardening crowd.  They are also much more focused on improving their bottom line which means increasing yields, decreasing costs and preferably both.  They buy in larger quantities (i.e. cubic feet, yards or by the ton) and are looking for much lower unit prices than gardeners.  While the costs for larger quantities is harder to pin down, it is still not close to the cost of other soil amendments.

In a recent plant trial that I was associated with, we used a commercial biochar which produced solid yield increases but when the cost of the biochar used in the potting mix was factored into the overall profit that would result from the two crops (i.e. lettuce and basil), the net financial result was negative for the farmer as compared to the net profit associated with the control in all but one scenario.    

While this is obviously only one trial, it is critical to consider the economics of yield increase versus cost increase.  Greenhouse growers generally do not reuse potting soil to reduce the spread of disease or because the potting soil is sold with the product.  To compete effectively in this market then, the price of biochar needs to come down to something that more closely mirrors the bulk cost of other potting soils used by greenhouse growers.



The CharCone: a great little kiln that will cook your food and help uncook the planet!

I am always flattered and excited when asked to do product reviews related to biochar.  Recently Bruce F. designed the CharCone, a mini Kon-Tiki geared towards the cooking crowd and asked if I’d be interested in taking it out for a test drive.

Bruce comes to the biochar world from a unique perspective.  A former chef and now a small business owner of SpitJack, he definitely knows his way around fire.  He also managed the sumptuous banquet at the US Biochar conference in Amherst which included some very unique biochar elements.  Bruce is very collaborative which isn’t overly common in the commercial world of biochar, so of course I agreed to test his kiln!

CharCone burn

The first burn I did was on a day which was too windy so I aborted before getting too close to the edge of the kiln.  Even so, about 5 gallons of char came out very nicely with only a few larger pieces that didn’t char through thoroughly (those just go in the next burn).  One trick with a small kiln is using easily bendable feedstock (e.g. dried reeds) to get a bed of coals going. This kind of fast burning feedstock is also good to use for the last 10 minutes or so of a burn as it keeps the fire going but doesn’t need a lot of time to fully char.

The second burn was on a perfect day wind-wise but a bit on the hot side!  Here are a few thoughts on using different feedstocks with the CharCone:

CharCone feedstock

  • Honeysuckle – this invasive shrub is a bit unwieldy but charring it is the best way to minimize its spread.  It is best to let it dry out for at least a few weeks, but even then it can take some care to safely use it.  It bends easily enough and burns great, but it unbends in the fire and often hangs over the side of the kiln, so it’s best to keep an eye on it at all times.
  • Old fence wood – burned fast.  If you use this sort of thing, make sure it is untreated wood so no nasty stuff gets airborne or into your soil.
  • Sawdust – a great starter feedstock as it makes an ember bed quickly; also good to use at the end to finish off the burn.  Make sure you don’t smother the flame though.  You may want to use a poker to move the sawdust around if it is clumpy as the sawdust might not fully burn otherwise.
  • Densified ethanol waste – Not something most people will have access too, but a local company asked me to make some char from this awhile back and I had some leftover.  This is a somewhat sticky, chunky feedstock which burns hot and for a relatively long time.  Seems to have completely charred through probably because I put it in about mid-burn.
  • Bones are a great source of renewable phosphorous or phosphates and calcium.  They take a while to burn so add them in early and make sure they don’t get covered over too quickly so they can char thoroughly.  If you are making char for soil use, add as many bones as you can find!
  • Lobster shells – thanks to a lavish Christmas dinner I have 2 buckets full of smelly lobster shells (even 5 months later they still smell!).  Lobster shells are also a good source of renewable calcium and a little something called chitin – a nitrogen rich polymer which has found use in everything from biomedicines to agriculture to golf balls.  [Fun fact: the world generates 6 – 8 M tons of crab, shell and lobster waste every year with most of it going to waste!] A biochar researcher friend of mine recently purchased chitin, which can be fairly expensive, to mix with his char.  Charring your own lobster shells is completely free and you get to enjoy a delicious lobster meal beforehand too! (Other research on pyrolyzing chitin shows it has promise as an electro catalyst with similar properties as platinum.)  These shells burn pretty quickly so they can be tossed on to the fire at almost any point.

A full burn took 1:45 and generates more than 10 gallons of what looks to be very good biochar.  Quenching the burn takes less than 5 gallons of water which is very handy.  The timing of feeding the fire is entirely dependent on what feedstock you are using.  If you are planning to cook, it would be better to use larger sticks so you don’t need to feed the fire so often.

What I really like about this kiln is its transportability.  With a few tools the legs can easily be taken off at which point the kiln fits nicely into the back of a car.  This makes it ideal for taking the CharCone to educational events or over to a friend’s house to help them char through yard debris while cooking a few hot dogs. With this kind of kiln you could also create a local Uber or CharB&Q for Kilns, which I believe Bruce has set up in Easthampton, MA. For more information on purchasing or renting kilns, check out the CharCone website.

Overall I highly recommend the CharCone!

Debunking the biochar = deforestation myth

Debunking biochar deforestation myth

The notion that scaling up biochar could lead to deforestation came up again recently in a discussion amongst some very well regarded biochar experts when we were talking about barriers to building the biochar industry.  While it is feasible that that could happen in countries that are already experiencing deforestation, it seems patently ridiculous to imply that biochar producers would cut down healthy trees and forests just to make biochar.  Not only is the value proposition lacking (as I’ve said before), but there is way too much available biomass that people, communities, and companies pay to get rid of that can be turned into biochar much more economically.  Off the top of my head here are the contenders for the top 10 sources of underutilized biomass in the USA:

  1. Sewage sludge:  The US generates something like 7 million dry tons of biosolids, often referred to as sewage sludge in its more raw form, every year.  This is the ultimate renewable feedstock as the population seems to only go up.  Roughly half of the biosolids are shipped off to landfills where it contributes to GHG emissions costing waste water treatment facilities a pretty penny. Biochar from biosolids research is promising and recent news claims that wastewater treatment facilities are starting to take this concept seriously.
  2. Livestock waste:  With ~90M cows, 200M hogs/pigs, 5.4M sheep and 2B assorted poultry, our domesticated bovine, porcine and poultry brethren create enormous amounts of biomass.  Although land application is often beneficial, in many places the nutrients found in livestock waste are causing havoc with water and air quality. Carbonizing manures can mitigate many environmental impacts while retaining valuable nutrients.
  3. Invasive Species: Like many countries around the world, the US has a growing problem with invasive species.  The cost of dealing with them combined with the loss in value of native flora has been estimated at $120B! Honeysuckle, barberry, Norway Maple, Kudzu, Wisteria are just a few species that are cut down, dug up, suffocated or in some cases burned in an attempt to rid regions of these pervasive plants. Training the army of volunteers that are fighting the war on invasives to char them on-site could go a long way towards reducing their spread.
  4. Beetle Kill etc: Globalization and global warming have both contributed to a growing pest problem which is devastating enormous amounts of standing biomass.  Millions of acres of pine, scotch, douglas fir, ash and other tree species have fallen prey to beetles, borers, fungi and other pathogens.  Dead trees not only blight urban, suburban and rural landscapes but they represent a severe fire hazard if not removed.  Fortunately some companies are already converting dead trees into biochar.
  5. Yard waste: An estimated 13.5% of what American’s send to the landfill is yard waste which translates to 34M tons of wasted organic matter.  Wood waste, presumably from deconstruction and other sources, represents another 6% of what we throw away.  Imagine if communities could convert this into biochar.  Not only would this reduce methane emissions from the decaying biomass, but transportation and tipping fees would be reduced and communities could use this biochar for their own landscaping needs.  The city of Stockholm, Sweden is one of the first in the world to start implementing this very notion!
  6. Industry waste: Many industries discard enormous amounts of organic waste including food processing, groceries, restaurants, etc.  In addition to food waste there is packaging waste (e.g. pallets, cardboard) which could be made into biochar if not recycled in other ways. The waste from just one product, coffee and the enormous industry it has spawned, is staggering. Americans drink nearly 3 billion pounds of coffee per year, and all but the liquid squeezed out of the coffee beans is treated as waste.  Rumor has it that some progressive coffee companies are starting to look at that as a potential feedstock for biochar!
  7. Crop waste – Every year in the US an estimated 1,239,000 hectares of crop residues are burned legally.  Residues from corn, cotton, rice, soybeans, sugar cane and more, are torched in an effort to cheaply clean up fields. Many of these residues could be converted into biochar and used to add carbon back to the soil and reduce leaching of nutrients into local water bodies.  Technologies such as the Iron Goat, a self-propelled, self-fueled gasifier could be modified do this sort of thing without the need for additional labor and with significantly less air pollution.
  8. Forestry thinnings – As the increasing number and severity of forest fires depletes firefighting budgets in the Western part of the US, massive amounts of forest thinnings are being culled from forests in an attempt to reduce risk of fires.  In Oregon and northern California alone some estimates claim that there is over 12 million green tons of available biomass from thinnings.  Much of this could be put to work making biochar.
  9. Storm debris – The number of winter blizzards has doubled in the past 20 years; hurricanes, thunderstorms and floods are also on the increase.  Each of these natural disasters cause enormous amounts of vegetative damage including downed trees, branches, and shrubs which is often chipped and shipped to far-off landfills. Converting storm debris into biochar could not only reduce removal costs, but with the right combination of technology could generate electricity locally which is often is scarce supply and could be used to remediate contaminated soils.
  10. Seaweed invasion – Over the past few years US & Caribbean beaches have been invaded by Sargassum seaweed. Governments and hotels have spent millions to remove the massive piles that wash up on shores, only for more to reappear days later.  One estimate said there was enough Sargassum seaweed to cover the entire state of Maryland! Dewatering and pyrolyzing this massive amount of endlessly renewable biomass could be an efficient way to stabilize fast forming carbon. Some work has been done on this already with promising results. Other aquatic invasives such as milfoil could also be charred and left around lakes they have invaded where it could prevent nutrients from leaching into the water.

There are undoubtedly more sources of unloved biomass than those I’ve outlined above, but this list should surely serve to debunk the myth that a thriving biochar industry would lead to deforestation.  To be sure each type of biomass requires different technologies and business models to make them financially viable, but fortunately we are already beginning to see activity in many of these areas.

The Biochar Displacement Strategy

cover v5Recently I had the honor of joining some of the gurus of biochar research at Cornell University at their one day Biochar/Bioenergy seminar.  I was asked to talk about something new & interesting so I took the liberty to talk about something I’ve been working on called The Biochar Displacement Strategy. Here is a modified version of my talk.

For many if not most in the biochar world, the focus to date has largely been on its use as a soil amendment which can sequester carbon long-term.  Since so far the market for sequestration products is still negligible and often only voluntary, and few if any markets have yet to officially recognize biochar as an offset product, there has been much attention paid to biochar’s value proposition in agriculture.  However given all the variables, not just on the biochar side, but with crops, soils, weather, etc. this has been a tough proposition to prove in many cases.  Some have seen greatly improved yields, while others have seen small or even negative impacts, at least in the short term.  While the nuances of which chars can best help which crops in which soils gets worked out, the imbalance of atmospheric to terrestrial carbon continues at our peril.

This focus on below ground applications seems unnecessarily restrictive to me when biochar or char or carbonized biomass or whatever you want to call it has so much more potential to offer in terms of climate change abatement. I tread lightly on how the term biochar is used here as I understand that many of the pioneers in the biochar realm prefer to restrict the definition of its use to adding it below our feet.  However for me the defining characteristic of biochar is its ability to sequester carbon for the long term.  Using this definition a world of opportunity opens up in terms of how biochar can be used to displace materials that have a large carbon footprint or are non-renewable or are toxic or otherwise harmful to the environment. I refer to this reframed perspective on biochar as the Biochar Displacement Strategy.

After the Paris talks there has been an increasing amount of chatter and hopefully action, on the topic of decarbonization.  The Montreal Carbon Pledge, the Portfolio Decarbonization Coalition and others are incentivizing investors to cut carbon out of the supply chain in various industries.  If we look at biochar through the lens of decarbonization, there are many displacement opportunities.  Activated carbon or charcoal is an obvious one and its use in all manner of filtration, remediation, deodorization, is an area which biochar is already being investigated. AC comes with a heavy carbon footprint, is often, though not always, made from non-renewable materials and its expensive.  Biochar can be customized to mimic many of the properties that make AC so useful for so many different applications and generally costs much less.  Another potential bonus when using biochar instead of AC to filter out valuable materials such as those found in food processing wastewater or aquaculture waste water, is that the char is actually enriched after the filtration process and can potentially be used in agriculture.  This is something that is being jointly worked on by the Rochester Institute of Technology and Cornell, where RIT is filtering tofu waste water using biochar and Cornell is testing the charged char as a growing medium. This is but one example of potential cascading uses for biochar – where biochar can be used more than once before it gets embedded in the soil.

Another high carbon footprint material that biochar could potentially displace is concrete – at least partially.  The use of biochar in concrete recipes can have some very positive effects beyond just lowering the embodied carbon including improved insulation and humidity control.  It can also reduce the weight of concrete which can be useful in some but not all applications.

Looking through the lens of displacing non-renewable materials biochar could be a feasible alternative to materials such as carbon black, a common ingredient in tires, conveyor belts, hoses, footwear, weather stripping, car bumpers. CB is also used as a color pigment for inks and has found uses in films, adhesives, magnetic tapes, garbage bags, agricultural mulch and so on.  The market for CB in tires alone is 12 billion pounds. Imagine the impact if we can design the right kind of biochar to displace this material which is made from sour gas, a highly polluting form of natural gas. Depending on the grade of CB, prices can range from $2,500 to $4,500 per ton, so biochar can definitely compete well on price.  If these biochar-based products end up in a landfill at the end of their life as many of the CB products do, the biochar will continue to sequester carbon.

Then there is the lens of displacing toxic or environmentally harmful materials with biochar.  In this category I include materials such as the prophylactic use of antibiotics in animal feed to boost feed conversion and maintain herd health.  While this practice may improve margins for CAFOs, it has some long term negative impacts on soils used to grow food as well as other implications for human health.  This is one of the most asked about areas of biochar usage amongst biochar producers and in Europe seems to be the most common use for biochar at the moment.framework2

The list of products that biochar could sustainably displace continues to grow as we learn more and more about the nuances of different types of biochars and how to create different properties through pre and post processing as well as different production parameters.  The good news is that I suspect many of these potential markets may be easier to crack in the short term than selling biochar to farmers.  Stay tuned for more news (perhaps even a book!) on the Biochar Displacement Strategy!

Could biochar roof tiles be coming soon to a roof near you?

roof tile overview

As the college year comes to a close the RIT senior design team focusing on biochar based roof tiles that I have been working with is showing some exciting results.  The team was tasked with coming up with a tile design as well as a biochar-concrete recipe which could be tested on homes being built by the 4 Walls Project in El Sauce, Nicaragua.  Each house is typically built by volunteers, family members of those receiving the house plus one skilled home builder and measures 6 x 6 meters. Currently the zinc roof is one of the more costly parts of the house ($400) and is one of the few parts that cannot be sourced locally. Zinc roofs are also loud when the heavy rains come and they conduct heat way too efficiently making the homes uncomfortably warm on hot days.

The challenge for the team was to design a roof that was cheaper, quieter and more insulating than the current roof.  Preferably they would design one that could be made locally thereby creating local jobs and spurring economic development, something which is sorely needed throughout the region.  While some testing still remains to be done, the design of the tiles has been finalized and the first several prototype tiles have been cast (see picture above).  The results are far more impressive than I think any of us were expecting!

The recipe chosen for the current batch includes roughly 30% biochar by volume (10% by weight).  Cement, sand and water make up most of the rest but the students sprinkle in some magic pixie dust – in the form of shredded plastic from soda bottles – to lend the tiles more strength.  The team even designed a handy little device to turn bottles into string – yet another possible job for locals in Nicaragua! Each tile contains roughly ½ of a 2 liter bottle’s worth of plastic.

A plastic mold was created for the tiles with a wood-like finish on the sunny side of the roof.  Current cost estimates put the entire roof at less than half the price of the zinc roof.  Although a realistic price on biochar has yet to be assessed, the amount of char needed could likely be made in one day using 1 or 2 Kon-Tiki soil kilns so in a place like Nicaragua where the cost of labor can be as low as $5/day, the cost of biochar would be negligible.  Plastic bottles are a nuisance, so putting a nominal fee on collecting them could go a long ways towards keeping them from cluttering up the landscape while also providing a steady stream of raw material for tile makers.

Not only could these biochar cement roofs be cheaper (see comparison of different roofing materials and their costs, weights and other properties here), but all indications are that they will be quieter and will help reduce heat gain as well.  That’s a sustainability trifecta as far as I can tell: People get more sleep due to less heat and noise; on the profit side homes will cost less and local jobs can be created; and the planet benefits from reduced mining for zinc, less waste from plastic bottles and up to ½ ton of CO2 gets sequestered in a single roof!

The students will be debuting their roof tiles May 7th at Imagine RIT! – the heat recovery team will also be showing off the tricked out Kon-Tiki as well!